1 #include<iostream>
  2 #include<cstring>
  3 #include<cstdio>
  4 #include<vector>
  5 #include<fstream>
  6 #include<queue>
  7 using namespace std;
  8 typedef long long LL;
  9 const int MAXN=6e5+10;
 10 const int N=3e5;
 11 const LL MOD=998244353;
 12 struct Edge{
 13     int to;
 14     LL w;
 15 };
 16 vector<Edge> edge[MAXN];
 17 int deg[MAXN]; 
 18 LL s[2];
 19 void dfs(int node,int pos, bool ext){
 20     //cout<<node<<‘ ‘<<s[0]<<‘ ‘<<s[1]<<‘ ‘<<deg[node]<<‘ ‘<<ext<<endl;
 21     for(int i=0;i<edge[node].size();i++){
 22         int p=edge[node][i].to;
 23         if(!deg[p])
 24             continue;
 25             
 26         if(deg[p]==2)
 27         {
 28             deg[node]--;
 29             deg[p]--;
 30             s[pos]=s[pos]*edge[node][i].w%MOD;
 31             dfs(p, pos^1, ext);    
 32             break;
 33         }
 34         else if(deg[node]==1&&deg[p]==1)
 35         {
 36             if(ext==false)
 37                 ext=true;
 38             else{
 39                 deg[node]--;
 40                 deg[p]--;
 41                 s[pos]=s[pos]*edge[node][i].w%MOD;
 42                 return;
 43             }
 44         }
 45     }
 46 }
 47 
 48 int main()
 49 {
 50     //ifstream cin("ylq.txt");
 51     int T;
 52     cin>>T;
 53     int n,v1,v2;
 54     LL w1,w2;
 55     Edge e1,e2;
 56     while(T--)
 57     {
 58         memset(deg, 0, sizeof(deg));
 59         //cin>>n;
 60         scanf("%d", &n);
 61         for(int i=1;i<=N+n;i++){
 62             edge[i].clear();
 63         }
 64         for(int i=1;i<=n;i++){
 65             //cin>>v1>>w1>>v2>>w2;
 66             scanf("%d %lld %d %lld", &v1, &w1, &v2, &w2);
 67             deg[v1+N]++;
 68             deg[v2+N]++;
 69             deg[i]+=2;
 70             
 71             e1.to=v1+N;e1.w=w1;
 72             e2.to=v2+N;e2.w=w2;
 73             edge[i].push_back(e1);
 74             edge[i].push_back(e2);
 75             
 76             e1.to=i;e2.to=i;
 77             edge[v1+N].push_back(e1);
 78             edge[v2+N].push_back(e2);
 79         }
 80         
 81         LL left=1;
 82         queue<int> q;
 83         for(int i=N;i<=n+N;i++)
 84             if(deg[i]==1)
 85                 q.push(i);
 86                 
 87         int m;
 88         while(!q.empty())
 89         {
 90             int p, pp;
 91             m=q.front(); q.pop();
 92             deg[m]=0;
 93             for(int i=0;i<edge[m].size();i++){
 94                 p=edge[m][i].to;
 95                 if(!deg[p])
 96                     continue;
 97                 else
 98                 {
 99                     deg[p]=0;
100                     left=left*edge[m][i].w%MOD;
101                     for(int k=0;k<edge[p].size();k++){
102                         pp=edge[p][k].to;
103                         if(deg[pp]==0) continue;
104                         
105                         deg[pp]--;
106                         if(deg[pp]==1)
107                             q.push(pp);
108                     }
109                 }
110             }
111              
112         }
113         //cout<<‘*‘<<left<<‘*‘<<endl;
114         LL ans=left;
115         for(int i=1;i<=n;i++){
116             if(!deg[i])
117                 continue;
118             s[0]=s[1]=1;
119             dfs(i, 1, 0);
120             ans=ans*(s[0]+s[1])%MOD;
121         }
122         
123         printf("%lld\n", ans);
124     }
125 }