#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#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>;




int main(){
    i64 N, M; cin >> N >> M;
    modint factN = 1;
    for(int i=1; i<=2*N; i++) factN *= i;
    modint comb = factN.inv();
    for(int i=M+1; i<=M+2*N; i++) comb *= i;

    modint ans = comb * M * N / (2*N+1);
    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;