#include <bits/stdc++.h>
#define lint __int128
#define int long long
#define Il inline
#define fi first
#define se second
#define vec vector
#define pb push_back
#define IT ::iterator
#define p_q priority_queue

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef double db;
const int N=1e6,mod=998244353;
const db eps=1e-9,pi=acos(-1.0);

mt19937 rnd(time(0));
Il int rint(int l,int r){return rnd()%(r-l+1)+l;}

Il int qpow(int x,int y){int t=1;for(;y;y>>=1,x=x*x%mod)if(y&1)t=t*x%mod;return t;}

int n,m,ans;

signed main(){
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n>>m;ans=n;for(int i=0;i<=(n<<1);i++)ans=ans*(m+i)%mod*qpow(i+1,mod-2)%mod;
    cout<<ans;
    return 0;
}