#include<bits/stdc++.h>

#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;

using ll = long long;
using P = pair<int , int>;
  
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  ll x; cin >> x;
  ll i, j;
  for(i = 0, j = 100; j < x; ++i) {
    j += (j/100);
  }
  cout << i;
}
  
