import java.lang.Math;
import java.util.Scanner;
class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        double interest = 100;
        int year = 0;
        while (interest < n){  
            year += 1;
            interest *= 1.01;
            interest = Math.floor(interest);
            if (interest >= n){
                break;
            }
        }
        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