n,k = map(int,input().split())
a = list(map(int,input().split()))
mod = 998244353

def f(x):
    res = 1
    for i in a:
        if i <= x:
            continue
        else:
            res *= x * pow(i,mod-2,mod) % mod
            res %= mod
    return res

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