import sys # sys.setrecursionlimit(200005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] inf = (1 << 63)-1 # inf = (1 << 31)-1 # md = 10**9+7 md = 998244353 from collections import defaultdict cc = [] for i in range(601): cc.append([1]) for j in range(1, i): cc[i].append((cc[i-1][j-1]+cc[i-1][j])%md) cc[i].append(1) # p2D(cc) n, m = LI() aa = LI() bb = LI() lim = 300*150+1 ans = 1 sc = defaultdict(int) sc[0] = 1 for si in range(m): dp = defaultdict(lambda: -1) for i in range(si, n, m): a, b = aa[i], bb[i] i = -a ndp = defaultdict(int) for c in cc[a+b]: if dp[i] == -1: ndp[i] = c elif dp[i]: ndp[i] = dp[i]*c%md i += 1 dp = ndp # pDB(i, a, b, dp) nsc = defaultdict(int) for d, v in dp.items(): for s, c in sc.items(): if -lim <= s+d <= lim: nsc[s+d] += v*c%md nsc[s+d] %= md sc = nsc print(sc[0])