#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int k = 1;
  int p = 0;
  while (n >= k) {
    n -= k;
    k *= 2;
    p++;
  }
  if (n > 0) {
    p++;
  }
  cout << p << endl;
  return 0;
}
