Vasya is going to hike with fellow programmers and decided to take a responsible approach to the choice of what he will take with him. Vasya has n things that he could take with him in his knapsack. Every thing weighs 1 kilogram. Things have different "usefulness" for Vasya.
The hiking is going to be very long, so Vasya would like to carry a knapsack of weight no more than w kilo.
Help him to determine the total "usefulness" of things in his knapsack if the weight of backpack can be no more than w kilo.
The first line contains integers w и n (1≤w,n≤20). The second line contains n integers ci (1≤ci≤1000) — the "usefulness" for each thing.
Print the total "usefulness" of things that Vasya can take with him.