/**

 problem: http://poj.org/problem?id=3259

 spfa判负环：

 当有个点被松弛了n次，则这个点必定为负环中的一个点（n为点的个数）

 spfa双端队列优化：

 维护队列使其dist小的点优先处理

 **/

 #include<stdio.h>

 #include<deque>

 #include<algorithm>

 using namespace std;

 class Graphics{

 const static int MAXN = ;

 const static int MAXM =  *  + ;

 const static int INF = 0x7fffffff;

 private:

     struct Edge{

         int to, dist, next;

     }edge[MAXM];

     int first[MAXN], sign, sumOfPoint;

 public:

     void init(int n){

         sumOfPoint = n;

         for(int i = ; i <= n; i ++){

             first[i] = -;

         }

         sign = ;

     }

     void addEdgeOneWay(int u, int v, int w){

         edge[sign].dist = w;

         edge[sign].to = v;

         edge[sign].next = first[u];

         first[u] = sign ++;

     }

     void addEdgeTwoWay(int u, int v, int w){

         addEdgeOneWay(u, v, w);

         addEdgeOneWay(v, u, w);

     }

     bool spfaNegRing(int start){

         bool *vis = new bool[sumOfPoint+];

         int *dist = new int[sumOfPoint+];

         int *cnt = new int[sumOfPoint+];

         for(int i = ; i <= sumOfPoint; i ++){

             vis[i] = ;

             cnt[i] = ;

             dist[i] = INF;

         }

         deque<int> que;

         que.push_front(start);

         dist[start] = ;

         vis[start] = ;

         while(!que.empty()){

             int now = que.front();

             que.pop_front();

             vis[now] = ;

             for(int i = first[now]; i != -; i = edge[i].next){

                 int to = edge[i].to, eDist = edge[i].dist;

                 if(dist[now] + eDist < dist[to]){

                     dist[to] = dist[now] + eDist;

                     cnt[to] ++;

                     if(cnt[to] >= sumOfPoint) { /// 如果这个点已经松弛n次则它必定是负环中的一个点

                         delete []vis; delete []dist; return true;

                     }

                     if(!vis[to]){

                         vis[to] = ;

                         if(que.empty() || dist[to] <= dist[que.front()])

                             que.push_front(to);

                         else

                             que.push_back(to);

                     }

                 }

             }

         }

         delete []vis; delete []dist; return false;

     }

 }graph;

 int main(){

     int f;

     scanf("%d", &f);

     while(f --){

         int n, m, w;

         scanf("%d%d%d", &n, &m, &w);

         graph.init(n);

         while(m --){

             int s, e, t;

             scanf("%d%d%d", &s, &e, &t);

             graph.addEdgeTwoWay(s, e, t);

         }

         while(w --){

             int s, e, t;

             scanf("%d%d%d", &s, &e, &t);

             graph.addEdgeOneWay(s, e, -t);

         }

         printf("%s\n", graph.spfaNegRing() ? "YES" : "NO");

     }

     return ;

 }