#include <bits/stdc++.h>
using namespace std;
int n, two, ans;
int main() {
  ios::sync_with_stdio(false);
  while (scanf("%d", &n) != EOF) {
    ans = 0;
    two = 1;
    while (n > 0) {
      ++ans;
      n -= two;
      two += two;
    }
    printf("%d\n", ans);
  }
  return 0;
}
