bool M1;
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<" MB\n"
#define look_time cerr<<(clock()-Time)*1.0/CLOCKS_PER_SEC<<'\n'
#include <cstdio>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <cstring>
#include <array>
#include <algorithm>
#include <queue>
#include <vector>
#include <bitset>
#include <ctime>
#include <cstdlib>
#include <random>
#include <set>
#include <ctime>
#include <map>
#include <stack>
#include <unordered_map>
#include <assert.h>
#define i128 __int128
#define ll long long
#define uint unsigned
#define ull unsigned long long
#define fo(a,b,c) for(ll a=b;a<=c;++a)
#define re(a,b,c) for(ll a=b;a>=c;--a)
#define pii pair<ll,ll>
#define pdd pair<db,db>
#define fi first
#define pb push_back
#define se second
#define ite set<ll> ::iterator
using namespace std;
const ll mod=1e9+7;
inline ll gi()
{
	ll x = 0, f = 1;
	char ch = getchar();
	while(ch < '0' || ch > '9')
	{
		if (ch == '-')
			f = -1;
		ch = getchar();
	}
	while(ch >= '0' && ch <= '9')
	{
		x = (x<<1) + (x<<3) + (ch^48);
		ch = getchar();
	}
	return x * f;
}
ll _=1;
const ll inf=2e17+5,iinf=2e9;
const ll N=1000005;
ll n,m,A,B;
vector<ll> g[N];
ll delt,dis[N],w[N];
struct st
{
	bool operator()(pii za,pii zb)
	{
		return za.fi>zb.fi;
	}
};
priority_queue<pii,vector<pii>,st> q;
ll dijm()
{
	while(!q.empty()) q.pop();
	fo(i,0,n) dis[i]=inf;
	dis[1]=0;
	q.push({0,1});
	while(!q.empty())
	{
		pii p=q.top();
		q.pop();
		ll u=p.se;
		for(ll v:g[u])
		{
			if(dis[v]>dis[u]+1&&w[v]<w[1]-delt*dis[u])
			{
				dis[v]=dis[u]+1;
				q.push({dis[v],v});
			}
		}
	}
	if(dis[n]>n) return -1;
	return dis[n];
}
ll dijx()
{
	while(!q.empty()) q.pop();
	fo(i,0,n) dis[i]=0;
	ll cnt=-1;
	q.push({0,1});
	while(!q.empty())
	{
		pii p=q.top();
		q.pop();
		ll u=p.se;
		if(dis[u]) continue;
		if(u==1||w[u]<w[1]+cnt*delt)
		{
			cnt++;
		}
		else
		{
			return 0;
		}
		dis[u]=1;
		for(ll v:g[u])
		{
			if(dis[v]==0) q.push({w[v],v});
		}
	}
	if(dis[n]) return 1;
	return 0;
}
ll lim[N];
ll dijn()
{
	while(!q.empty()) q.pop();
	fo(i,0,n) dis[i]=inf;
	dis[1]=0;
	fo(i,2,n)
	{
		ll z=w[i]-w[1]+1;
		if(z<=0)
		{
			lim[i]=-inf;
			continue;
		}
		ll num=z/delt;
		if(z%delt) num++;
		lim[i]=num;
	}
	q.push({0,1});
	while(!q.empty())
	{
		pii p=q.top();
		q.pop();
		ll u=p.se;
		for(ll v:g[u])
		{
			if(dis[v]>max(lim[v]+1,dis[u]+1))
			{
				dis[v]=max(lim[v]+1,dis[u]+1);
				q.push({dis[v],v});
			}
		}
	}
	return dis[n];
}
void sol()
{
	n=gi(),m=gi(),A=gi(),B=gi();
	fo(i,1,n) g[i].clear();
	ll ok1=0;
	fo(i,1,m)
	{
		ll x=gi(),y=gi();
		g[x].pb(y);
		g[y].pb(x);
		if(x==1&&y==n) ok1=1;
		if(x==n&&y==1) ok1=1;
	}
	fo(i,1,n) w[i]=gi();
	fo(i,2,n) w[i]+=B;
	if(w[1]>w[n]) ok1|=2;
	if(A<=B)
	{
		delt=B-A;
		ll ans=dijm();
		if(ans==-1&&ok1==3)
		{
			cout<<"TEST 1";
			return;
		}
		cout<<ans;
		return;
	}
	delt=A-B;
	if(dijx())
	{
		cout<<dijn();
		return;
	}
	cout<<-1;
}
bool M2;
int main()
{
//	freopen("monster.in","r",stdin);
//	freopen("monster.out","w",stdout);
	int Time=clock();
	look_memory;
	_=gi();
	while(_--)
	{
		sol();
		printf("\n");
	}
	look_time;
	return 0;
}