import java.util.*;
import java.io.*;
public class Main {

	public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	}
}
 	
 
//StringJoiner sj = new StringJoiner(" "); 
//sj.add(strings)
//sj.toString() gives string of those stuff w spaces or whatever that sequence is

 		
 		
 		
 		
	

 import java.util.*; util.* java import java.io.*; io.* java public class Main {

	public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	}
} Main public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	} main {
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	} int num = 998244353; num 998244353 BufferedReader bf = new BufferedReader(new InputStreamReader(System.in)); bf new BufferedReader(new InputStreamReader(System.in)) PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) long t = Long.parseLong(bf.readLine()); t Long.parseLong(bf.readLine()) Long.parseLong Long bf.readLine() bf.readLine bf long j = 100; j 100 int count = 0; count 0 while(j < t){
 			count++;
 			j = j+j/100;
 		} j < t j t {
 			count++;
 			j = j+j/100;
 		} count++ count j = j+j/100 j j+j/100 j j/100 j 100 out.println(count) out.println out count out.close() out.close out String[] args args public class Main {

	public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	}
} public class Main {

	public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	}
} Main
import java.util.*;
import java.io.*;
public class Main {

	public static void main(String[] args) throws Exception{
		int num = 998244353;

		// TODO Auto-generated method stub
 		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
 		PrintWriter out = new PrintWriter(System.out);
 		long t = Long.parseLong(bf.readLine());
 		long j = 100;
 		int count = 0;
 		while(j < t){
 			count++;
 			j = j+j/100;
 		}
 		out.println(count);
 		out.close();
 	}
}
 	
 
//StringJoiner sj = new StringJoiner(" "); 
//sj.add(strings)
//sj.toString() gives string of those stuff w spaces or whatever that sequence is

 		
 		
 		
 		
	


