#include <bits/stdc++.h>
int main() {
  long long n;
  scanf("%lld", &n);
  long long cnt(0);
  for (long p = 1; p <= n; p *= 2) {
    n -= p;
    ++cnt;
  }
  cnt += (n > 0);
  printf("%lld\n", cnt);
  return 0;
}
