#include <bits/stdc++.h>
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define precise(i) fixed << setprecision(i)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

int main() {
  fastIO;
  int n;
  cin >> n;

  long long int sum = 1;
  int cnt = 0;
  while (true) {
    if (sum >= n) {
      break;
    }
    sum *= 2;
    cnt++;
  }

  cout << cnt << '\n';
  return 0;
}