//package atcoder;
 
import java.util.*;
 
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long rishi = 100;
		long count = 0;
		//System.out.println(Math.pow(1.01, 2));
		while(rishi<X) {
			rishi = (long) Math.floor(rishi*1.01);
			count ++;
			//System.out.println(count);
		}
		System.out.println(count);
		}
		
	}

/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