import java.util.*;
class Main {
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        }
        }
/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