#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n;
  cin >> n;
  long long c = 0;
  long long flag = 1;
  long long sum = 0;
  while (flag) {
    long long p = (long long)pow(2, c);
    if ((sum + p) >= n) {
      break;
    } else {
      sum += p;
      c++;
    }
  }
  cout << c + 1;
  return 0;
}
