# include <bits/stdc++.h>
# define speed ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
# pragma GCC optimize "-O3"
# define int long long
  
using namespace std;
  
const int N = 1e4 + 7;
const int mod = 1e9 + 7;

void solve() {
	int x;
	cin >> x;
	int y = 100, cnt = 0;
	while ( y < x ) {
		cnt++;
		int z = y / 100 * 1;
		y += z;
	}
	cout << cnt << "\n";
}

int32_t main() {
	speed;
	int T = 1;
	// cin >> T;
	while ( T-- ) {
		solve();
	}
}