#include<bits/stdc++.h>
using namespace std;
using ll=long long;

#include<atcoder/modint>
using namespace atcoder;
using mint=modint998244353;

vector<mint> fact, factinv, inv;
const ll mod = 998244353;
void prenCkModp(ll n) {
    fact.resize(n + 5);
    factinv.resize(n + 5);
    inv.resize(n + 5);
    fact[0] = fact[1] = 1;
    factinv[0] = factinv[1] = 1;
    inv[1] = 1;
    for (ll i = 2; i < n + 5; i++) {
        fact[i] = (fact[i - 1] * i);
        inv[i] = mod - (inv[mod % i] * (mod / i));
        factinv[i] = (factinv[i - 1] * inv[i]);
    }

}

mint nCk(ll n, ll k) {
    if (n < k||k<0) return 0;
    return fact[n] * (factinv[k] * factinv[n - k]);
}

int main(){
	ios::sync_with_stdio(false);
    cin.tie(nullptr);

    
    ll N,M;
    cin>>N>>M;
    prenCkModp(N);
    vector<mint> dp(N,0);
    for(int i=0;i<N;i++)dp[i]=nCk(N-1,i);
    for(int i=0;i<M-1;i++){
        vector<mint> ndp(N,0);
        mint s=0;
        for(int k=0;k<N;k++)s+=dp[k];
        for(int j=0;j<N;j++){
            ndp[j]=s*2;
            
            ndp[j]*=nCk(N-1,j);
        }
        swap(dp,ndp);
    }
    mint an=0;
    for(int i=0;i<N;i++)an+=dp[i];
    cout<<an.val()<<"\n";
}