import java.util.*;

class Main {
    private static Scanner sc;

    public static void main(final String[] args) {
        sc = new Scanner(System.in);
        long a = sc.nextLong(),ans = 0,num = 100;
        while(true){
            if(num >= a){
                System.out.println(ans);
                break;
            }  
            num += num/100;
            ans++;
        }
    }
}







/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