codeforces#P1230A. Dawid and Bags of Candies
Dawid and Bags of Candies
Description
Dawid has four bags of candies. The $i$-th of them contains $a_i$ candies. Also, Dawid has two friends. He wants to give each bag to one of his two friends. Is it possible to distribute the bags in such a way that each friend receives the same amount of candies in total?
Note, that you can't keep bags for yourself or throw them away, each bag should be given to one of the friends.
The only line contains four integers $a_1$, $a_2$, $a_3$ and $a_4$ ($1 \leq a_i \leq 100$) — the numbers of candies in each bag.
Output YES if it's possible to give the bags to Dawid's friends so that both friends receive the same amount of candies, or NO otherwise. Each character can be printed in any case (either uppercase or lowercase).
Input
The only line contains four integers $a_1$, $a_2$, $a_3$ and $a_4$ ($1 \leq a_i \leq 100$) — the numbers of candies in each bag.
Output
Output YES if it's possible to give the bags to Dawid's friends so that both friends receive the same amount of candies, or NO otherwise. Each character can be printed in any case (either uppercase or lowercase).
Samples
1 7 11 5
YES
7 3 2 5
NO
Note
In the first sample test, Dawid can give the first and the third bag to the first friend, and the second and the fourth bag to the second friend. This way, each friend will receive $12$ candies.
In the second sample test, it's impossible to distribute the bags.