import java.util.ArrayList;
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();

        long prop = 100;
        int count = 0;
        double rate = 1.01;

        while(true){
            if(prop<X){
                prop *= rate; count++;
            } else { 
                break;
            }
        }

        System.out.println(count);

        sc.close();
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz