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

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

mod = 998244353

N,M = mi()

memo = {0:[1],1:[1,1]}
def calc(M):
    if M in memo:
        return memo[M]
    if M < 0:
        return [0]
    
    res = [0] * 30
    A = calc((M-1)//2)
    for i in range(len(A)):
        if A[i]:
            res[i+1] += A[i]
            res[i+1] %= mod
    B = calc(M//2)
    for i in range(len(B)):
        res[i] += B[i]
        res[i] %= mod
    
    memo[M] = res
    return res

cnt = calc(M)
res = 0
for k in range(len(cnt)):
    res += pow(N,k,mod) * cnt[k] % mod
    res %= mod

print(res)