#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <array>
#include <atcoder/modint>

using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)


const i64 INF = 1001001001001001001;
using modint = atcoder::static_modint<998244353>;


modint f(u64 N, u64 M){
    if(M == 0) return 1;
    u64 d = 1;
    u64 logd = 0;
    while((d<<1) <= M){ d<<=1; logd++; }
    modint ans = 0;
    ans += modint(N+1).pow(logd);
    ans += f(N, M-d) * modint(N);
    return ans;
}


int main(){
    int N, M; cin >> N >> M;
    auto ans = f(N, M);
    cout << ans.val() << '\n';
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;