F

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

const int INF = 0x3f3f3f3f;
const int maxn = 50005;
int n, w, m, k, dis[maxn];

struct node
{
    int u, v, w;
    node() {}
    node(int uu, int vv, int ww): u(uu), v(vv), w(ww) {}
}edge[maxn];

bool Bellman_Ford(int s)
{
    for(int i = 1; i <= n; i++) dis[i] = INF;
    dis[s] = 0;
    for(int i = 0; i < n; i++)
    {
        int flag = 1;
        for(int j = 0; j < k; j++)
        {
            int u = edge[j].u;
            int v = edge[j].v;
            int w = edge[j].w;
            if(dis[u] + w < dis[v])
            {
                flag = 0;
                dis[v] = dis[u]+w;
                if(i == n-1)
                    return true;
                //如果循环n-1次还能缩，就存在负环
            }
        }
        if(flag) return false;
    }
    return false;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t;
    cin >> t;
    while(t--)
    {
        k = 0;
        scanf("%d%d%d", &n, &m, &w);
        for(int i = 1; i <= m+w; i++)
        {
            int u, v, w;
            scanf("%d%d%d", &u, &v, &w);
            if(i <= m)
            {
                edge[k++] = node(u, v, w);
                edge[k++] = node(v, u, w);
            }
            else edge[k++] = node(u, v, -w);
        }
        if(Bellman_Ford(1)){
            cout << "YES" << endl;
        }
        else
            cout << "NO" << endl;
    }
    return 0;
}