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


dp = [0]*k
dp[0] = 1

for i in range(k):

    ndp = [0]*k

    for j in range(k):
        if dp[j] == 0:
            continue

        yellow = i - j*2
        if yellow:
            ndp[j+1] += dp[j] * yellow
            ndp[j+1] %= mod

        if (n-yellow) > 0:
            ndp[j] += dp[j] * (n-yellow)
            ndp[j] %= mod
    
    dp = ndp

ans = 0
for i in range(k):
    ans += (n+i) * dp[i]
    ans %= mod

inv = pow(n,k,mod)
ans *= pow(inv,mod-2,mod)
ans %= mod

print(ans)