#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
typedef long long ll;
using namespace std;

int main(){
    ll y = 0;
    ll x;
    ll d = 100;
    cin >> x;
    while(d < x) {
        y++;
        d *= 1.01;
    }
    cout << y << endl;
}
