#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  long long int n;
  cin >> n;
  int b = 1, c = 0;
  for (; b < n; n -= b, b *= 2, c++)
    ;
  cout << c + (n > 0 ? 1 : 0) << endl;
  return 0;
}
