You are given four integer numbers as input, and you are given function maxOfTwo(a, b) that takes two integers and returns the maximum of them.

You need to define function maxOfFour(a, b, c, d) that takes in four integers and returns the maximum of them.

Constraints

You are not allowed to use if conditions or any comparison logic, you are only allowed to call maxOfTwo(a, b) that returns the maximum of two numbers inside your function.

Example 1

Input

1 2 3 4

Output

4

Example 2

Input

50 10 60 20

Output

60

Example 3

Input

100 1000 10 0

Output

1000