def pow(x, n, c):
    if n == 0:
        return [1, 0]

    if n == 1:
        return [x, 0]

    [y, c] = pow(x, n // 2, c)

    if n % 2 == 0:
        return [y * y, c + 1]
    return [y * y * x, c + 2]