Func<int, int, int> Sum = (x, y) => x + y;
Func<int, int, int> Minus = (x, y) => x - y;
Func<int, int, int> Multiply = (x, y) => x * y;
Func<int, int, int> Divide = (x, y) => x / y;
Func<int, int, int> Modulo = (x, y) => x % y;