Equal Subset Sum

Given four integers, determine whether there exists a non-empty subset of these integers that sums up exactly to half of the total sum of the four numbers.

Let \(S\) be the total sum of the four integers, i.e. \(S = b_1 + b_2 + b_3 + b_4\). You need to determine if there exists a subset whose sum is \(\frac{S}{2}\). Note that if \(S\) is odd, then no such subset can exist.

Read the input from STDIN and print the result to STDOUT. Output "YES" if such a subset exists and "NO" otherwise.

inputFormat

The input consists of a single line containing four space-separated integers b₁, b₂, b₃, and b₄.

outputFormat

Output a single line containing "YES" if there exists a subset of the four numbers that sums to half of their total sum; otherwise, output "NO".

2 4 6 8

YES