#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;
ul over = 1000000007;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  ll a, b;
  ll n;
  cin >> n;
  ll now = 1;
  ll ans = 0;
  while (now < n) {
    now *= 2;
    ans++;
  }
  cout << ans << endl;
  return 0;
}