n,k = map(int,input().split()) mod = 998244353 ### for bigger prime N = n+5 fact = [1]*N finv = [1]*N for i in range(2,N): fact[i] = (fact[i-1]*i)%mod finv[-1] = pow(fact[-1],mod-2,mod) for i in range(1,N)[::-1]: finv[i-1] = (finv[i]*i)%mod def nCr(n,r): if r > n: return 0 else: return fact[n]*finv[r]%mod*finv[n-r]%mod 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 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)