def cmb(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    return (g1[n] * g2[r] % mod) * g2[n-r] % mod

mod = 998244353
N = 2*10**5
g1 = [1]*(N+1)
g2 = [1]*(N+1)
inverse = [1]*(N+1)

for i in range( 2, N + 1 ):
    g1[i]=( ( g1[i-1] * i ) % mod )
    inverse[i]=( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2[i]=( (g2[i-1] * inverse[i]) % mod )
inverse[0]=0


import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import e, log,gcd

input = lambda :sys.stdin.readline()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

mod = 998244353

N,M = mi()

dp = [[0 for j in range(N+1)] for i in range(N+1)]

for i in range(1,N+1):
    dp[i][1] = 1
    for j in range(2,N+1):
        dp[i][j] = (dp[i-1][j-1] + dp[i-1][j] * j) % mod

res = 0
for i in range(1,N+1):
    COMB = 1
    tmp = 0
    for j in range(1,min(N,M+1)+1):
        tmp += g1[j] * (dp[i][j] * COMB % mod) % mod
        tmp %= mod
        COMB = COMB * ((M+2-j) * inverse[j] % mod) % mod
    res += tmp * cmb(N,i,mod) * pow(M+1,N-i,mod) % mod
    res %= mod
        #for mex in range(1,j+1):
            #res += g1[j] * dp[i][j] * cmb(M+1-mex,j-mex,mod) * cmb(N,i,mod) * pow(M+1,N-i,mod) % mod
            #res %= mod

print(res)