#include<bits/stdc++.h>
#define int long long
using namespace std;
inline int read()
{
	int s=0,w=1;
	char c=getchar();
	while(c<'0'||c>'9')
	{
		if(c=='-')w=-1;
		c=getchar();
	}
	while(c>='0'&&c<='9')s=(s<<3)+(s<<1)+(c^48),c=getchar();
	return s*w;
}
inline void print(int x)
{
	if(x<0)x=-x,putchar('-');
	if(x>=10)print(x/10);
	putchar(x%10+48);
}
int T,n,m,p,w[1000010];
struct edge
{
	int x,res,money;
	bool operator<(const edge &a)const
	{
		if(res==a.res)return money>a.money;
		return res<a.res;
	}
}f[1000010];
int g[810][810],vis[810];
edge inf={0,0x3f3f3f3f3f3f3f3f,-0x3f3f3f3f3f3f3f3f};
priority_queue<edge> q;
inline void init()
{
	for(int i=0;i<=n;i++)f[i]=inf;
	memset(vis,0,sizeof(vis));
	f[1]={1,0,p};
	q.push(f[1]);
}
inline void work()
{
	while(q.size())
	{
		edge now=q.top();
		q.pop();
		if(vis[now.x])continue;
		vis[now.x]=1;
		int u=now.x;
		//cout<<"u:"<<u<<"\n"; 
		for(int v=1;v<=n;v++)
		{
			if(g[u][v]==g[1][0]||vis[v])continue;
			int Res=now.res,Money=now.money;
			if(Money>=g[u][v])
			{
				Money-=g[u][v];
			}
			else
			{
				int xuyao=(g[u][v]-Money+w[u]-1)/w[u];
				Res+=xuyao;
				Money+=xuyao*w[u];
				Money-=g[u][v];
			}
			edge res={v,Res,Money};
			//cout<<"wmhakioi:"<<v<<" "<<Res<<" "<<Money<<"\n";
			if(f[v]<res)
			{
				//puts("DeaphetS");
				f[v]=res;
				q.push(f[v]);
			}
		}
	}
}
signed main()
{
	T=read();
	while(T--)
	{
		n=read();
		m=read();
		p=read();
		memset(g,0x3f,sizeof(g));
		for(int i=1;i<=n;i++)
		{
			w[i]=read();
			g[i][i]=0;
		}
		for(int i=1;i<=m;i++)
		{
			int u=read(),v=read(),w=read();
			g[u][v]=w;
		}
		for(int k=1;k<=n;k++)
		{
			for(int i=1;i<=n;i++){
				for(int j=1;j<=n;j++)
				{
					g[i][j]=min(g[i][j],g[i][k]+g[k][j]);
				}
			}
		}
		init();
		work();
		if(f[n].x==0)
		{
			puts("-1");
			continue;
		}
		print(f[n].res);
		puts("");
	}
}