#include <algorithm>
#include <string.h>
#include <iostream>
#include <stdio.h>

using namespace std;

typedef long long ll;
ll n;
ll s = 100;
ll res = 0;

int main() {
	cin >> n;

	while (s < n) {
		s += s / 100;
		res++;
	}

	cout << res << endl;

	return 0;
}