int power(int n, int k) {
  if (k == 0)
    return 1;
  else if (k % 2) // k = 2m + 1, m ≥ 0
    return n * power(n, k - 1);
  else // k = 2m, m > 0
    return power(n * n, k / 2);
}

void task2() {
  int n, k;

  cout << "Input n: "; cin >> n;
  cout << "Input k: "; cin >> k;

  if (k < 0)
    cout << "k < 0";
  else
    cout << "n^k = " << power(n, k);

  cout << endl;
}