#include <bits/stdc++.h>

using namespace std;

int main() {
  long long n, x = 1, cnt = 0;
  scanf("%lld", &n);
  while (x < n) {
    x *= 2;
    cnt++;
  }
  while (x != n) {
    x--;
    cnt++;
  }
  printf("%lld\n", cnt);
  return 0;
}