# mod バージョン

N, K = map(int, input().split())
mod = 998244353

K_inv = pow(K, mod-2, mod)
prob = 1
for i in range(N-2):
    prob *= K_inv
    prob %= mod
prob *= (K-1)
prob %= mod
prob *= K_inv
prob %= mod
prob *= N
prob %= mod
print(prob)