#include<stdio.h>
#include<string.h>
#include<queue>
#define MAX 100000
#define INF 0x3f3f3f
using namespace std;
int head[MAX];
int n,m,s,ans;
int dis[MAX],vis[MAX];
int used[MAX];
struct node
{
	int u,v,w;
	int next;
}edge[MAX];
void add(int u,int v,int w)
{
	edge[ans].u=u;
	edge[ans].v=v;
	edge[ans].w=w;
	edge[ans].next=head[u];
	head[u]=ans++;
}
void init()
{
	ans=0;
	memset(head,-1,sizeof(head));
}
void getmap()
{
	int i,j;
	while(m--)
	{
		int a,b,c;
		scanf("%d%d%d",&a,&b,&c);
		add(a,b,c);
	}
	while(s--)
	{
		int a,b,c;
		scanf("%d%d%d",&a,&b,&c);
		add(b,a,-c);
	}
}
void spfa(int sx)
{
	int i,j;
	queue<int>q;
	memset(vis,0,sizeof(vis));
	memset(used,0,sizeof(used));
	for(i=1;i<=n;i++)
	    dis[i]=i==sx?0:INF;
	vis[sx]=1;
	used[sx]++;
	q.push(sx);
	while(!q.empty())
	{
		int u=q.front();
		q.pop();
		vis[u]=0;
		for(i=head[u];i!=-1;i=edge[i].next)
		{
			int top=edge[i].v;
			if(dis[top]>dis[u]+edge[i].w)
			{
				dis[top]=dis[u]+edge[i].w;
				if(!vis[top])
				{
					vis[top]=1;
					q.push(top);
					used[top]++;
					if(used[top]>n)
					{
						printf("-1\n");
						return ;
					}
				}
			}
		}
	}
	if(dis[n]==INF)
	printf("-2\n");
	else
	printf("%d\n",dis[n]);
}
int main()
{
	int t;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%d%d%d",&n,&m,&s);
		init();
		getmap();
		spfa(1);
	}
	return 0;
}