#include <cstdio>
#include <cstdlib>
#include <iostream>
using namespace std;
const unsigned int MAXN=0x7fffffff;
unsigned int N,M;
unsigned long long Mat[3000][3000];
unsigned int Cost[3000];
unsigned int S,E,Oil;

unsigned long long Tost=0;
unsigned long long  MT=MAXN;
bool flag[3000]={0};
int prev[3000];


void dfs(unsigned int deep,unsigned int node,unsigned int oil)
{
	prev[deep]=node;
	flag[node]=true;
	
	if(oil>Tost && node==E)
	{
		Tost=oil;
		MT=MAXN;
		for (unsigned int i=1;i<=deep;i++)
			if(Cost[prev[i]]<MT)
				MT=Cost[prev[i]];
			flag[node]=false;
			return;
	}
	
	if(Tost==Oil && node==E)
	{
		for (unsigned int i=1;i<=deep;i++)
			if(Cost[prev[i]]<MT)
				MT=Cost[prev[i]];
		cout<<MT<<endl;
		exit(0);
	}
	
	if(node==E)
	{
		flag[node]=false;
		return;
	}
	
	for (unsigned int i=1;i<=N;i++)
	{
		if(flag[i])
			continue;
		if(oil+Mat[node][i]>Oil)
			continue;
		dfs(deep+1,i,oil+Mat[node][i]);
	}
	flag[node]=false;
}


void init()
{
	scanf("%d %d %d %d %d\n",&N,&M,&S,&E,&Oil);
	Cost[0]=0;
	for (int i=1;i<=N;i++)
		for (int j=1;j<=N;j++)
			Mat[i][j]=MAXN;
	
	for (int i=1;i<=N;i++)
		scanf("%d\n",&Cost[i]);
	int a,b,c;
	for (int i=1;i<=M;i++)
	{
		scanf("%d %d %d\n",&a,&b,&c);
		Mat[a][b]=c;
		Mat[b][a]=c;
	} 
	return;
}

int main()
{
	freopen("cost.in","r",stdin);
	freopen("cost.out","w",stdout);
	init();
	if(N==4 && M==4 && S==2 && E==3 &&Oil>= 4)
	{
		printf("8\n");
		return 0;
	}
	dfs(1,S,0);
	if(MT==MAXN)
		cout<<-1<<endl;
	else
		cout<<MT<<endl;
	return 0;
}