#!/usr/bin/env PyPy3

from collections import Counter, defaultdict, deque
import itertools
import re
import math
from functools import reduce
import operator
import bisect
import heapq
import functools
mod=998244353

import sys
input=sys.stdin.readline

n,k=map(int,input().split())
ans = 0
ans2 = 0
for i in range(1,k+1):
    ans += i * n * (k - i) % mod * (pow(i,n-1,mod) - pow(i-1,n-1,mod)) % mod
    ans %= mod
    tmp = ((pow(i,n,mod) - pow(i-1,n,mod)) % mod - n * pow(i-1,n-1,mod)) % mod
    ans += i * tmp
    ans %= mod
print(ans)