#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, i, j, c = 0, k = 1;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    k = k * 2;
    c++;
    if (k > n) break;
  }
  cout << c << endl;
  return 0;
}
