#include<bits/stdc++.h>
#define Gc() getchar() 
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;using LL=__int128;
const int N=2e6+5,M=N*20+5,K=600+5,mod=998244353,Mod=mod-1;const db eps=1e-9;const ll INF=1e18+7;mt19937 rnd(time(0));
int n,Sum[N];char s[N];
void Solve(){
	int i,j;scanf("%d",&n);
	scanf("%s",s+1);
	for(i=1;i<=2*n;i++){
		Sum[i]=Sum[i-1]+(s[i]=='W'?1:-1);
	}
	int LA=0,flag=0;
	ll ans=1;
	for(i=1;i<=2*n;i++) if(!Sum[i]){
		int Ct=0;flag++;
		for(j=i;j>LA;j--){
			if(s[j]==s[i])  Ct++;
			else ans=ans*Ct%mod,Ct--;
		} 
		for(j=LA+1;j<i;j++){
			if(s[j]^s[i]) Ct++;
			else Ct--,ans=ans*Ct%mod;
		}
		if(i-LA>2) ans=ans*(mod+1)/2%mod;
		LA=i;
	}
	ans=ans*max(1,flag-1)%mod;
	printf("%lld\n",ans%mod);
}
int main(){
	int t;
	scanf("%d",&t);
	// t=1;
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}