#include <bits/stdc++.h>
using namespace std;
int main() {
  double K;
  cin >> K;
  int N = K;
  int count = 0;
  while (K > 1) {
    K = K / (2.0);
    count++;
  }
  if (N % 2 == 0) {
    cout << count << endl;
  } else {
    cout << count << endl;
  }
}
