#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <climits>#include <string>#include <iostream>#include <map>#include <cstdlib>#include <list>#include <set>#include <queue>#include <stack>using namespace std;typedef long long LL;const int maxm = 10000 + 5;const int maxn = 500 + 5;const int INF = INT_MAX / 2;int u[maxm],v[maxm],w[maxm],cnt;int first[maxn],nxt[maxm];int N,M,W,d[maxn],inq[maxn];bool vis[maxn];bool bellmanford() {    //bellmanford判环原理是，如果经过了N轮操作还能继续松弛，则出现了负环    for(int i = 1;i <= N;i++) {        d[i] = INF;    }    d[1] = 0;    for(int i = 1;i <= N;i++) {        bool flag = false;        for(int j = 1;j <= cnt;j++) {            if(d[v[j]] > d[u[j]] + w[j]) {                d[v[j]] = d[u[j]] + w[j];                flag = true;            }        }        //已经不能松弛了        if(flag == false) return false;    }    for(int j = 1;j <= cnt;j++) {        if(d[v[j]] > d[u[j]] + w[j]) return true;    }    return false;}bool spfa() {    //spfa 的思想是，如果一个节点的入队次数大于N，那么肯定有负环    memset(inq,0,sizeof(inq));    memset(vis,0,sizeof(vis));    for(int i = 1;i <= N;i++) d[i] = INF;    d[1] = 0;    queue<int> q;    q.push(1);    inq[1] = 1;    while(!q.empty()) {        int x = q.front(); q.pop();        vis[x] = false;        for(int i = first[x];i != 0;i = nxt[i])  {            if(d[v[i]] > d[x] + w[i]) {                d[v[i]] = d[x] + w[i];                if(!vis[v[i]]) {                    q.push(v[i]);                    inq[v[i]]++;                    vis[v[i]] = true;                    if(inq[v[i]] > N) return true;                }            }        }    }    return false;}void adde(int _u,int _v,int _w) {      cnt++;    u[cnt] = _u; v[cnt] = _v; w[cnt] = _w;    nxt[cnt] = first[_u];    first[_u] = cnt;}int main() {    int F; scanf("%d",&F);    while(F--) {        memset(first,0,sizeof(first));        memset(nxt,0,sizeof(nxt));        cnt = 0;        scanf("%d%d%d",&N,&M,&W);        for(int i = 1;i <= M;i++) {            int a,b,c; scanf("%d%d%d",&a,&b,&c);            adde(a,b,c);            adde(b,a,c);        }        for(int i = M + 1;i <= M + W;i++) {            int a,b,c;            scanf("%d%d%d",&a,&b,&c);            adde(a,b,-c);        }        bool ret = spfa();        if(ret) puts("YES");        else puts("NO");    }    return 0;}