//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
int t,n,m;
ll A,B;
ll l[200200];
vector<int> G[200200];
int dist[200200];
int vis1[200200],vis2[200200];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>t;
	while(t--)
	{
		cin>>n>>m>>A>>B;
		for(int i=1;i<=n;i++)
			G[i].clear();
		for(int i=1;i<=m;i++)
		{
			int u,v;
			cin>>u>>v;
			G[u].pb(v);
			G[v].pb(u);
		}
		for(int i=1;i<=n;i++)
		{
			cin>>l[i];
			if(i>1)
				l[i]+=B;
		}
		if(A<=B)
		{
			for(int i=1;i<=n;i++)
				dist[i]=-1;
			queue<int> q;
			dist[1]=0;
			q.push(1);
			while(!q.empty())
			{
				int x=q.front();
				q.pop();
				for(auto y:G[x])
					if(dist[y]==-1&&l[y]+B*dist[x]<l[1]+A*dist[x])
					{
						dist[y]=dist[x]+1;
						q.push(y);
					}
			}
			cout<<dist[n]<<'\n';
		}
		else
		{
			for(int i=1;i<=n;i++)
				vis1[i]=vis2[i]=0;
			int cnt=0;
			queue<int> q;
			priority_queue<pii,vector<pii>,greater<pii>> pq;
			q.push(1);
			vis1[1]=vis2[1]=1;
			for(auto j:G[1])
			{
				vis2[j]=1;
				pq.emplace(l[j],j);
			}
			while(!q.empty())
			{
				int x=q.front();
				q.pop();
				cnt++;
				while(!pq.empty()&&pq.top().first<l[1]+(A-B)*(cnt-1))
				{
					int u=pq.top().second;
					vis1[u]=1;
					q.push(u);
					pq.pop();
					for(auto v:G[u])
						if(!vis2[v])
						{
							vis2[v]=1;
							pq.emplace(l[v],v);
						}
				}
			}
			if(!vis1[n])
				cout<<"-1\n";
			else
			{
				for(int i=1;i<=n;i++)
					dist[i]=inf;
				priority_queue<pii,vector<pii>,greater<pii>> pq;
				dist[1]=0;
				pq.emplace(0,1);
				while(!pq.empty())
				{
					int x=pq.top().second;
					int d=pq.top().first;
					pq.pop();
					if(dist[x]!=d) continue;
					for(auto y:G[x])
						if(vis1[y])
						{
							int nd=max(d+1ll,(l[y]>=l[1])?(max(0ll,l[y]-l[1])/(A-B)+2):0);
							if(nd<dist[y])
							{
								dist[y]=nd;
								pq.emplace(nd,y);
							}
						}
				}
				cout<<dist[n]<<'\n';
			}
		}
	}
	return 0;
}