Subsets with Fixed Average

You are given an array of n integers. Your task is to count the number of non-empty subsets of the given array with average equal to a. Input The first line has two integers n and a: the size of the array and the target average. The next line has n integers x_1, x_2,\dots, x_n: the contents of the array. Output Print one integer: the number of non-empty subsets with average equal to a, modulo