import sys
input = sys.stdin.readline

N,M=list(map(int,input().split()))

mod=998244353

# x以下でbit_countの個数が配列K

from functools import lru_cache
@lru_cache(maxsize=None)
def calc(x):
    if x==0:
        return [1]+[0]*29

    A=calc(x//2)
    B=calc((x-1)//2)

    K=[0]*30

    for i in range(29):
        K[i]+=A[i]
        K[i+1]+=B[i]

    return K

X=calc(M)
ANS=0

for i in range(30):
    ANS+=pow(N,i,mod)*X[i]
    ANS%=mod

print(ANS)