//package beg_165;
import java.util.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner a = new Scanner(System.in);
		long b = a.nextLong();
		
		int i=0;
		long total=100;
		while (total<b) {
			long c =  total/100;
			total=total+c;
			//System.out.println(total);
			i++;
		}
		System.out.println(i);
	}

}

/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