#include <bits/stdc++.h>
using namespace std;
const int oo = 1000000007;
const int nn = 100010;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int res = 0, p = 1;
  while (n > 0) {
    res++;
    n -= p;
    p *= 2;
  }
  cout << res;
}
