#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int Mod=998244353;
int T,ans=1;
ll qpow(ll p,ll n){
	ans=1;
	while(n>0){
		if(n&1)ans=(ans*p%Mod+Mod)%Mod;
		p=(p*p%Mod+Mod)%Mod;
		n>>=1;
	}
	return ans%Mod;
}
void work(){
	int n;
	string s;
	cin>>n>>s;
	if(n==2)cout<<1<<endl;
	else if(n==3)cout<<4<<endl;
	else {
		cout<<qpow(2,n)<<endl; 
	}
}
int main(){
	cin>>T;
	while(T--)work();	
	return 0;
}