import java.util.*;

public class Main {
    public static void main(String[] args) {
        Long x, y = (long)100;
        Long n = (long)0;
        Scanner sc = new Scanner(System.in);
        x = sc.nextLong();
        while (y < x){
            Long i = y / (long)100;
            n++;
            y += i;
            //System.out.println("kekka" + y);
        }
        System.out.println(n);
    }
}
/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