#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, t = 1, i = 1;
  cin >> n;
  if (n == 1) {
    cout << 1 << endl;
    return 0;
  }
  n--;
  while (true) {
    if (i * 2 > n) {
      break;
    }
    n = n - (2 * i);
    i = 2 * i;
    t++;
  }
  if (n == 0) {
    cout << t << endl;
  } else {
    cout << t + 1 << endl;
  }
  return 0;
}
