#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  int sum = 1;
  int cnt = 0;
  while (true) {
    cnt++;
    if (sum * 2 >= N) {
      break;
    }
    sum *= 2;
  }
  if (N == 1) {
    cnt = 0;
  }
  cout << cnt << endl;
  getchar();
}