//package beg_165;
import java.util.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

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

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

} Main public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	} main {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	} Scanner a = new Scanner(System.in); a new Scanner(System.in) long b = a.nextLong(); b a.nextLong() a.nextLong a int i=0; i 0 long total=100; total 100 while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		} total<b total b {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		} long c =  total/100; c total/100 total 100 total=total+c total total+c total c i++ i System.out.println(i) System.out.println System.out System System.out i String[] args args public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

} public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

} Main
//package beg_165;
import java.util.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

}
