mod = 998244353
n, k = map(int, input().split())
a = list(map(int, input().split()))
def f(x):
    res = 1
    for ai in a:
        res *= min(x, ai) * pow(ai, mod - 2, mod)
        res %= mod
    return res

ans = (f(k) - f(k - 1)) % mod
print(ans)