public Input()
{
add = new Addition();
minus = new Subtraction();
mult = new Multiply();
div = new Division();
}
public CalculatorBody()
{
this.sum = new Addition();
this.difference = new Subtraction();
this.product = new Multiplication();
this.quotient = new Division();
this.exponent = new Exponentiation();
this.sqrt = new SquareRoot();
this.input = new UserInputOutput();
}