B'All bus tickets in Berland have their numbers. A number consists of n digits ( n is even). Only k decimal digits d_1, d_2, ... , d_k can be used to form ticket numbers. If 0 is among these digits, then numbers may have leading zeroes. For example, if n = 4 and only digits 0 and 4 can be used, then 0000 , 4004 , 4440 are valid ticket numbers, and 0002 , 00 , 44443 are not. A ticket is lucky if the sum of first n / 2 digits is equal to the sum of remaining n / 2 digits. Calculate the number of different lucky tickets in Berland. Since the answer may be big, print it modulo 998244353 . The first line contains two integers n and k (2 <= n <= 2 cdot 10^5, 1 <= k <= 10) -- the number of digits in each ticket number, and the number of different decimal digits that may be used. n is even. The second line contains a sequence of pairwise distinct integers d_1, d_2, ... , d_k (0 <= d_i <= 9) -- the digits that may be used in ticket numbers. The digits are given in arbitrary order. Print the number of lucky ticket numbers, taken modulo 998244353 . In the first example there are 6 lucky ticket numbers: 1111 , 1818 , 1881 , 8118 , 8181 and 8888 . There is only one ticket number in the second example, it consists of 20 digits 6 . This ticket number is lucky, so the answer is 1 . '...