N,K = map(int, input().split())
A = list(map(int, input().split()))
pt1 = 1
mod = 998244353
pt2 = 1
pt3 = 1
for i in A:
    pt1 *= i
    pt1 %= mod
    pt2 *= min(K,i)
    pt2 %= mod
    pt3 *= min(K-1,i)
    pt3 %= mod
pt4 = (pt2-pt3)%mod
print(pt4*pow(pt1,-1,mod)%mod)