#include <bitset>
#include <iostream>

using namespace std;

//template <unsigned int x>
//constexpr int log2() {
//  return x < 4 ? 1 : 1 + log2<x / 2>();
//}

constexpr int log2(const unsigned int x) {
  return x < 4 ? 1 : 1 + log2(x / 2);
}

int main() {
  bitset<log2(2)> foo;
  int bar[log2(8)];

  cout << log2(8) << endl;
}