import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    } main {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long a = 100; a 100 for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        } long i = 0; long i = 0; i 0 i < X i X i++ i++ i {
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        } {
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        } a += a/100 a a/100 a 100 if(a >= X){
                System.out.print(i + 1);
                i = X;
            } a >= X a X {
                System.out.print(i + 1);
                i = X;
            } System.out.print(i + 1) System.out.print System.out System System.out i + 1 i 1 i = X i X String[] args args public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    }
} Main
import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long a = 100;
        
        for(long i = 0; i < X;i++){
            a += a/100;
            if(a >= X){
                System.out.print(i + 1);
                i = X;
            }
        }
    
    }
}