$rt$ ，

#include<bits/stdc++.h>
#define ll long long
using namespace std;
const ll N=998244353;
ll t,n;
string s;
signed main(){
	cin>>t;
	while(t--){
		cin>>n>>s;
        if (n==1)cout<<2<<endl;
        if (n==2)cout<<1<<endl;
        if (n==3)cout<<4<<endl;
		if (n>=4){
			ll ans=1;
			for(int i=1;i<=n;i++)ans*=2;
			cout<<ans%N<<endl; 
		}
	}
	return 0;
}