#include<bits/stdc++.h>
using namespace std;
#define mx 100009
#define ll long long int
vector<ll>v[mx];
ll n,m,cr,cl;
bool vis[mx];
ll ans[mx];
ll res=0;
ll dfs(int s)
{
    vis[s]=true;
    for(ll i=0;i<v[s].size();i++){
        if(vis[v[s][i]]==false){
            ans[v[s][i]]=min(ans[s]+cr,ans[s]+cl);
            ans[s]=ans[v[s][i]];
            res=max(res,ans[v[s][i]]);
            vis[v[s][i]]=true;
            dfs(v[s][i]);
        }
    }
    return res;
}
int main()
{
    ll q;
    cin>>q;
    while(q--){
        memset(vis,false,sizeof(vis));
        memset(v,0,sizeof(v));
        memset(ans,0,sizeof(ans));
        cin>>n>>m>>cl>>cr;
        for(int i=0;i<m;i++){
            ll a,b;
            cin>>a>>b;
            v[a].push_back(b);
            v[b].push_back(a);
        }
        ll ppp=0;
        for(int i=1;i<=n;i++){
            if(vis[i]==false){
                ans[i]=cl;
                res=ans[i];
                ppp+=dfs(i);
            }
        }
        cout<<ppp<<endl;
    }
}