#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

ll N, M = 1, cnt;

int main() {
  cin >> N;
  while (M < N) {
    M *= 2;
    cnt++;
  }
  cout << cnt << endl;
  return 0;
}