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