import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;

public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	}

	static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	}

}

class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		}
		return true;
	}

	private byte readByte() {
		if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		}
	}

	private boolean isPrintableChar(int c) {
		return '!' <= c && c <= '~';
	}

	private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		}
	}

	public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	}

	public String next() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		StringBuilder sb = new StringBuilder();
		byte b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public int nextInt() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		int n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

	public long nextLong() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		long n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

} import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.NoSuchElementException; NoSuchElementException java.util public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	}

	static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	}

} Main public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	} main {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	} FastScanner sc = new FastScanner(); sc new FastScanner() PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		} long i = (long) Math.sqrt(n); long i = (long) Math.sqrt(n); i (long) Math.sqrt(n) Math.sqrt Math n i > 0 i 0 i-- i-- i {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		} {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		} if (n % i == 0) {
				out.println(digit(n / i));
				break;
			} n % i == 0 n % i n i 0 {
				out.println(digit(n / i));
				break;
			} out.println(digit(n / i)) out.println out digit(n / i) digit n / i n i break; out.flush() out.flush out String[] args args static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	} digit {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	} int d = 0; d 0 while (n > 0) {
			n /= 10;
			d++;
		} n > 0 n 0 {
			n /= 10;
			d++;
		} n /= 10 n 10 d++ d return d; d long n n class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		}
		return true;
	}

	private byte readByte() {
		if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		}
	}

	private boolean isPrintableChar(int c) {
		return '!' <= c && c <= '~';
	}

	private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		}
	}

	public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	}

	public String next() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		StringBuilder sb = new StringBuilder();
		byte b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public int nextInt() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		int n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

	public long nextLong() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		long n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

} FastScanner private final InputStream in = System.in; in System.in System System.in private final byte[] buffer = new byte[1024]; buffer new byte[1024] 1024 private int ptr = 0; ptr 0 private int buflen = 0; buflen 0 private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		}
		return true;
	} hasNextByte {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		}
		return true;
	} if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		} ptr < buflen ptr buflen {
			return true;
		} return true; true {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		} ptr = 0 ptr 0 try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			} IOException e {
				e.printStackTrace();
			} e.printStackTrace() e.printStackTrace e {
				buflen = in.read(buffer);
			} buflen = in.read(buffer) buflen in.read(buffer) in.read in buffer if (buflen <= 0) { return false; } buflen <= 0 buflen 0 { return false; } return false; false return true; true private byte readByte() {
		if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		}
	} readByte {
		if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		}
	} if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		} hasNextByte() hasNextByte {
			return buffer[ptr++];
		} return buffer[ptr++]; buffer[ptr++] buffer ptr++ ptr {
			return -1;
		} return -1; -1 1 private boolean isPrintableChar(int c) {
		return '!' <= c && c <= '~';
	} isPrintableChar {
		return '!' <= c && c <= '~';
	} return '!' <= c && c <= '~'; '!' <= c && c <= '~' '!' <= c '!' c c <= '~' c '~' int c c private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		}
	} skipUnprintable {
		while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		}
	} while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		} hasNextByte() && !isPrintableChar(buffer[ptr]) hasNextByte() hasNextByte !isPrintableChar(buffer[ptr]) isPrintableChar(buffer[ptr]) isPrintableChar buffer[ptr] buffer ptr {
			ptr++;
		} ptr++ ptr public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	} hasNext {
		skipUnprintable();
		return hasNextByte();
	} skipUnprintable() skipUnprintable return hasNextByte(); hasNextByte() hasNextByte public String next() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		StringBuilder sb = new StringBuilder();
		byte b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	} next {
		if (!hasNext()) { throw new NoSuchElementException(); }
		StringBuilder sb = new StringBuilder();
		byte b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	} if (!hasNext()) { throw new NoSuchElementException(); } !hasNext() hasNext() hasNext { throw new NoSuchElementException(); } throw new NoSuchElementException(); new NoSuchElementException() StringBuilder sb = new StringBuilder(); sb new StringBuilder() byte b = readByte(); b readByte() readByte while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		} isPrintableChar(b) isPrintableChar b {
			sb.appendCodePoint(b);
			b = readByte();
		} sb.appendCodePoint(b) sb.appendCodePoint sb b b = readByte() b readByte() readByte return sb.toString(); sb.toString() sb.toString sb public int nextInt() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		int n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	} nextInt {
		if (!hasNext()) { throw new NoSuchElementException(); }
		int n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	} if (!hasNext()) { throw new NoSuchElementException(); } !hasNext() hasNext() hasNext { throw new NoSuchElementException(); } throw new NoSuchElementException(); new NoSuchElementException() int n = 0; n 0 boolean minus = false; minus false byte b = readByte(); b readByte() readByte if (b == '-') {
			minus = true;
			b = readByte();
		} b == '-' b '-' {
			minus = true;
			b = readByte();
		} minus = true minus true b = readByte() b readByte() readByte if (b < '0' || '9' < b) { throw new NumberFormatException(); } b < '0' || '9' < b b < '0' b '0' '9' < b '9' b { throw new NumberFormatException(); } throw new NumberFormatException(); new NumberFormatException() while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		} true {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		} if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			} '0' <= b && b <= '9' '0' <= b '0' b b <= '9' b '9' {
				n *= 10;
				n += b - '0';
			} n *= 10 n 10 n += b - '0' n b - '0' b '0' if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			} b == -1 || !isPrintableChar(b) b == -1 b -1 1 !isPrintableChar(b) isPrintableChar(b) isPrintableChar b {
				return minus ? -n : n;
			} return minus ? -n : n; minus ? -n : n minus -n n n {
				throw new NumberFormatException();
			} throw new NumberFormatException(); new NumberFormatException() b = readByte() b readByte() readByte public long nextLong() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		long n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	} nextLong {
		if (!hasNext()) { throw new NoSuchElementException(); }
		long n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	} if (!hasNext()) { throw new NoSuchElementException(); } !hasNext() hasNext() hasNext { throw new NoSuchElementException(); } throw new NoSuchElementException(); new NoSuchElementException() long n = 0; n 0 boolean minus = false; minus false byte b = readByte(); b readByte() readByte if (b == '-') {
			minus = true;
			b = readByte();
		} b == '-' b '-' {
			minus = true;
			b = readByte();
		} minus = true minus true b = readByte() b readByte() readByte if (b < '0' || '9' < b) { throw new NumberFormatException(); } b < '0' || '9' < b b < '0' b '0' '9' < b '9' b { throw new NumberFormatException(); } throw new NumberFormatException(); new NumberFormatException() while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		} true {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		} if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			} '0' <= b && b <= '9' '0' <= b '0' b b <= '9' b '9' {
				n *= 10;
				n += b - '0';
			} n *= 10 n 10 n += b - '0' n b - '0' b '0' if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			} b == -1 || !isPrintableChar(b) b == -1 b -1 1 !isPrintableChar(b) isPrintableChar(b) isPrintableChar b {
				return minus ? -n : n;
			} return minus ? -n : n; minus ? -n : n minus -n n n {
				throw new NumberFormatException();
			} throw new NumberFormatException(); new NumberFormatException() b = readByte() b readByte() readByte public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	}

	static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	}

} public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	}

	static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	}

} Main
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;

public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);

		long n = sc.nextLong();
		for (long i = (long) Math.sqrt(n); i > 0; i--) {
			if (n % i == 0) {
				out.println(digit(n / i));
				break;
			}
		}

		out.flush();
	}

	static int digit(long n) {
		int d = 0;
		while (n > 0) {
			n /= 10;
			d++;
		}
		return d;
	}

}

class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) { return false; }
		}
		return true;
	}

	private byte readByte() {
		if (hasNextByte()) {
			return buffer[ptr++];
		} else {
			return -1;
		}
	}

	private boolean isPrintableChar(int c) {
		return '!' <= c && c <= '~';
	}

	private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
			ptr++;
		}
	}

	public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	}

	public String next() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		StringBuilder sb = new StringBuilder();
		byte b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public int nextInt() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		int n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

	public long nextLong() {
		if (!hasNext()) { throw new NoSuchElementException(); }
		long n = 0;
		boolean minus = false;
		byte b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) { throw new NumberFormatException(); }
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}

}