B. Appleman and Card Gametime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputAppleman has n cards. Each card has an uppercase letter written on it. Toastman must choose k cards from Appleman's cards. Then Appleman should give Toastman some coins depending on the chosen cards. Formally, for each Toastman's card i you should calculate how much Toastman's cards have the letter equal to letter on ith, then sum up all these quantities, such a number of coins Appleman should give to Toastman.Given the description of Appleman's cards. What is the maximum number of coins Toastman can get?InputThe first line contains two integers n and k (1 ≤ k ≤ n ≤ 105). The next line contains n uppercase letters without spaces — the i-th letter describes the i-th card of the Appleman.OutputPrint a single integer – the answer to the problem.ExamplesInput15 10DZFDFZDFDDDDDDFOutput82Input6 4YJSNPIOutput4NoteIn the first test example Toastman can choose nine cards with letter D and one additional card with any letter. For each card with D he will get 9 coins and for the additional card he will get 1 coin.
Input15 10DZFDFZDFDDDDDDF
Output82
['greedy', '*1300']