#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
#define met(a,b) memset(a,b,sizeof a)
#define pb push_back
#define mp make_pair
#define inf 0x3f3f3f3f
#define qwer 2e18
using namespace std;
typedef long long ll;
const int N = 6e5+50;
const int M = 16000009;
const int mod = 998244353;
const double pi= acos(-1.0);
typedef pair<int,int>pii;
int n,s;
int vis[N],in[N];
ll ans[2];
vector<pii>edg[N];
ll topSort(){
    queue<int>q;
    ll ret=1;
    for(int i=n+1;i<=n+n;i++){
        if(in[i]==1){
            q.push(i);
            vis[i]=1;
        }
    }
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for(int i=0;i<edg[u].size();i++){
            int v=edg[u][i].first;
            if(vis[v])continue;
            if((--in[v])==1)q.push(v),vis[v]=1;
            if(u>n)ret=(ret*1LL*edg[u][i].second)%mod;
        }
    }
    return ret;
}
void dfs(int u,int ty,int fa){
    vis[u]=1;
    for(int i=0;i<edg[u].size();i++){
        int v=edg[u][i].first;
        if(v==s&&v!=fa)ans[ty]=(ans[ty]*1LL*edg[u][i].second)%mod;
        if(vis[v])continue;
        ans[ty]=(ans[ty]*1LL*edg[u][i].second)%mod;
        dfs(v,ty^1,u);
    }
}
int main(){
    //freopen("de.txt","r",stdin);
    int T;
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i=0;i<N;i++)vis[i]=in[i]=0,edg[i].clear();
        for(int i=1,v1,w1,v2,w2;i<=n;i++){
            scanf("%d%d%d%d",&v1,&w1,&v2,&w2);
            v1+=n;v2+=n;
            edg[i].pb(mp(v1,w1));
            edg[v1].pb(mp(i,w1));
            edg[i].pb(mp(v2,w2));
            edg[v2].pb(mp(i,w2));
            in[i]+=2;
            in[v1]++;in[v2]++;
        }
        ll anss=topSort();
        for(s=1;s<=n;s++){
            if(!vis[s]){
                ans[0]=ans[1]=1;
                dfs(s,0,0);
                anss=anss*((ans[0]+ans[1])%mod)%mod;
            }
        }
        printf("%lld\n",anss);
    }
    return 0;
}