#include <bits/stdc++.h>
using namespace std;
const int mod = (1e9) + 7;
const double eps = 1e-6;
const int siz = 1e5 + 5, siz2 = 1e5 + 5;
int n;
int main() {
  scanf("%d", &n);
  long long l = 1, tot = 0;
  int c = 0;
  while (tot < n) {
    tot += l;
    l *= 2;
    c++;
  }
  printf("%d\n", c);
  return 0;
}
