"""Calculator for Math"""

class CalculatorMath:
    def __init__(self):
        pass

    def add(self, x, y):
        return x + y

    def subtract(self, x, y):
        return x - y

    def multiply(self, x, y):
        return x * y

    def divide(self, x, y):
        if y == 0:
            return "Error! Division by zero."
        return x / y

    def power(self, x, y):
        return x ** y

    def square_root(self, x):
        import math
        if x < 0:
            return "Error! Square root of negative number."
        return math.sqrt(x)

    def modulus(self, x