import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
"""mod = 998244353
nn = 3*10**5
fact = [1] * nn
for i in range(nn - 1):
    fact[i + 1] = fact[i] * (i + 1) % mod
invfact = [1] * nn
invfact[nn - 1] = pow(fact[nn - 1], mod - 2, mod)
for i in range(nn - 1)[::-1]:
    invfact[i] = invfact[i + 1] * (i + 1) % mod
 
def binom(x, y):
    if x < 0 or y < 0 or x - y < 0:
        return 0
    return fact[x] * invfact[y] % mod * invfact[x - y] % mod"""
n,k = na()
f = [0]*(k+1)
mod = 998244353
for i in range(k+1):
    f[i] = (pow(k, n, mod)-n*(k-i)*pow(i,n-1,mod)-pow(i,n,mod))%mod
#print(f)
ans = 0
for i in range(k):
    f[i] -= f[i+1]
    f[i] %= mod
    ans += f[i]*(i+1)%mod
    ans %= mod
print(ans)