N,M=map(int,input().split())
MOD=998244353

ans=0
v=1
K=M.bit_length()-1
for i in range(K,-1,-1):
  if (M>>i)&1:
    ans+=pow(N+1,i,MOD)*v%MOD
    ans%=MOD
    v*=N
    v%=MOD
ans+=v
ans%=MOD
print(ans)