#include <bits/stdc++.h>
using namespace std;
int main() {
  int i = 0, j = 1, n, k = 0, p;
  cin >> n;
  p = (n / 2) + 1;
  while (1) {
    if (p > pow(2, k)) {
      i++;
      k++;
    } else
      break;
  }
  cout << i + 1 << endl;
}
