import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	} main {
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long money=100; money 100 int s=0; s 0 while(money<X){
        	money+=money/100;
        	s++;
        } money<X money X {
        	money+=money/100;
        	s++;
        } money+=money/100 money money/100 money 100 s++ s System.out.println(s) System.out.println System.out System System.out s String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	}
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
		long X = sc.nextLong();
        long money=100;
      	int s=0;
        
        
        while(money<X){
        	money+=money/100;
        	s++;
        }
		System.out.println(s);
		
	}
}