
import java.util.*;
import java.io.*;
public class Main {
	static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } 
	private static final int mod =(int)1e9+7;
	public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	}
	static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	}
	} import java.util.*; util.* java import java.io.*; io.* java public class Main {
	static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } 
	private static final int mod =(int)1e9+7;
	public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	}
	static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	}
	} Main private static final int mod =(int)1e9+7; mod (int)1e9+7 (int)1e9 7 public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	} main {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	} Reader sc=new Reader(); sc new Reader() PrintWriter out=new PrintWriter(System.out); out new PrintWriter(System.out) long n=sc.nextLong(); n sc.nextLong() sc.nextLong sc int ans=0; ans 0 int res=Integer.MAX_VALUE; res Integer.MAX_VALUE Integer Integer.MAX_VALUE for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
} long i=1; long i=1; i 1 i*i<=n i*i i i n i++ i++ i {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
} {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
} if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	} n%i==0 n%i n i 0 {
		ans=Math.max(cntd(i),cntd(n/i));		
	} ans=Math.max(cntd(i),cntd(n/i)) ans Math.max(cntd(i),cntd(n/i)) Math.max Math cntd(i) cntd i cntd(n/i) cntd n/i n i res=Math.min(res,ans) res Math.min(res,ans) Math.min Math res ans out.print(res) out.print out res out.println() out.println out out.flush() out.flush out String[] args args static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	} cntd {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	} int ans=0; ans 0 while(n!=0) {
						ans++;
						n/=10;
							} n!=0 n 0 {
						ans++;
						n/=10;
							} ans++ ans n/=10 n 10 return ans; ans long n n static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } Reader final private int BUFFER_SIZE = 1 << 16; BUFFER_SIZE 1 << 16 1 16 private DataInputStream din; din private byte[] buffer; buffer private int bufferPointer bufferPointer bytesRead; bytesRead public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } Reader { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } din = new DataInputStream(System.in) din new DataInputStream(System.in) buffer = new byte[BUFFER_SIZE] buffer new byte[BUFFER_SIZE] BUFFER_SIZE bufferPointer = bytesRead = 0 bufferPointer bytesRead = 0 bytesRead 0 public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } Reader { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } din = new DataInputStream(new FileInputStream(file_name)) din new DataInputStream(new FileInputStream(file_name)) buffer = new byte[BUFFER_SIZE] buffer new byte[BUFFER_SIZE] BUFFER_SIZE bufferPointer = bytesRead = 0 bufferPointer bytesRead = 0 bytesRead 0 String file_name file_name public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } readLine { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } byte[] buf = new byte[64]; buf new byte[64] 64 int cnt = 0 cnt 0 c; c while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } (c = read()) != -1 (c = read()) c read() read -1 1 { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } if (c == '\n') 
                 break; c == '\n' c '\n' break; buf[cnt++] = (byte) c buf[cnt++] buf cnt++ cnt (byte) c return new String(buf, 0, cnt); new String(buf, 0, cnt) public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } nextInt { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } int ret = 0; ret 0 byte c = read(); c read() read while (c <= ' ') 
             c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg) 
             c = read(); neg c = read() c read() read do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' { 
             ret = ret * 10 + c - '0'; 
         } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (neg) 
             return -ret; neg return -ret; -ret ret return ret; ret public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } nextLong { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } long ret = 0; ret 0 byte c = read(); c read() read while (c <= ' ') 
             c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg) 
             c = read(); neg c = read() c read() read do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' { 
             ret = ret * 10 + c - '0'; 
         } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (neg) 
             return -ret; neg return -ret; -ret ret return ret; ret public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } nextDouble { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } double ret = 0 ret 0 div = 1; div 1 byte c = read(); c read() read while (c <= ' ') 
             c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg) 
             c = read(); neg c = read() c read() read do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' { 
             ret = ret * 10 + c - '0'; 
         } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } c == '.' c '.' { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' { 
                 ret += (c - '0') / (div *= 10); 
             } ret += (c - '0') / (div *= 10) ret (c - '0') / (div *= 10) (c - '0') c '0' (div *= 10) div 10 if (neg) 
             return -ret; neg return -ret; -ret ret return ret; ret private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } fillBuffer { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE) bytesRead din.read(buffer, bufferPointer = 0, BUFFER_SIZE) din.read din buffer bufferPointer = 0 bufferPointer 0 BUFFER_SIZE if (bytesRead == -1) 
             buffer[0] = -1; bytesRead == -1 bytesRead -1 1 buffer[0] = -1 buffer[0] buffer 0 -1 1 private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } read { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } if (bufferPointer == bytesRead) 
             fillBuffer(); bufferPointer == bytesRead bufferPointer bytesRead fillBuffer() fillBuffer return buffer[bufferPointer++]; buffer[bufferPointer++] buffer bufferPointer++ bufferPointer public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } close { 
         if (din == null) 
             return; 
         din.close(); 
     } if (din == null) 
             return; din == null din null return; din.close() din.close din public class Main {
	static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } 
	private static final int mod =(int)1e9+7;
	public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	}
	static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	}
	} public class Main {
	static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } 
	private static final int mod =(int)1e9+7;
	public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	}
	static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	}
	} Main

import java.util.*;
import java.io.*;
public class Main {
	static class Reader 
 { 
     final private int BUFFER_SIZE = 1 << 16; 
     private DataInputStream din; 
     private byte[] buffer; 
     private int bufferPointer, bytesRead; 

     public Reader() 
     { 
         din = new DataInputStream(System.in); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public Reader(String file_name) throws IOException 
     { 
         din = new DataInputStream(new FileInputStream(file_name)); 
         buffer = new byte[BUFFER_SIZE]; 
         bufferPointer = bytesRead = 0; 
     } 

     public String readLine() throws IOException 
     { 
         byte[] buf = new byte[64]; // line length 
         int cnt = 0, c; 
         while ((c = read()) != -1) 
         { 
             if (c == '\n') 
                 break; 
             buf[cnt++] = (byte) c; 
         } 
         return new String(buf, 0, cnt); 
     } 

     public int nextInt() throws IOException 
     { 
         int ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do
         { 
             ret = ret * 10 + c - '0'; 
         }  while ((c = read()) >= '0' && c <= '9'); 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     public long nextLong() throws IOException 
     { 
         long ret = 0; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 
         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 
         if (neg) 
             return -ret; 
         return ret; 
     } 

     public double nextDouble() throws IOException 
     { 
         double ret = 0, div = 1; 
         byte c = read(); 
         while (c <= ' ') 
             c = read(); 
         boolean neg = (c == '-'); 
         if (neg) 
             c = read(); 

         do { 
             ret = ret * 10 + c - '0'; 
         } 
         while ((c = read()) >= '0' && c <= '9'); 

         if (c == '.') 
         { 
             while ((c = read()) >= '0' && c <= '9') 
             { 
                 ret += (c - '0') / (div *= 10); 
             } 
         } 

         if (neg) 
             return -ret; 
         return ret; 
     } 

     private void fillBuffer() throws IOException 
     { 
         bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
         if (bytesRead == -1) 
             buffer[0] = -1; 
     } 

     private byte read() throws IOException 
     { 
         if (bufferPointer == bytesRead) 
             fillBuffer(); 
         return buffer[bufferPointer++]; 
     } 

     public void close() throws IOException 
     { 
         if (din == null) 
             return; 
         din.close(); 
     } 
 } 
	private static final int mod =(int)1e9+7;
	public static void main(String[] args) throws Exception  {
Reader sc=new Reader();
PrintWriter out=new PrintWriter(System.out);
long n=sc.nextLong();
int ans=0;
int res=Integer.MAX_VALUE;
for(long i=1;i*i<=n;i++) {
	if(n%i==0) {
		ans=Math.max(cntd(i),cntd(n/i));		
	}
	res=Math.min(res,ans);
}
out.print(res);
out.println();
out.flush();

	}
	static int cntd(long n) {
							int ans=0;
							while(n!=0) {
						ans++;
						n/=10;
							}
							return ans;
	}
	}