import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x= sc.nextLong();
        long sum = 100;
        int y = 0;

        while(true){
            if(sum>=x){
                break;
            }
            y++;
            sum = sum + (long)Math.floor(sum*0.01);       
        }

            System.out.println(y);
    }
}

/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