import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;



public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			long ru=sc.nextLong();
			long val=100;
			long n=0;
			while(val<ru) {
				val+=val/100;
				n++;
			}
			System.out.println(n);
			
			
		}
		
		System.out.println(out);
	}
	
 
	
}
/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