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#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define endl "\n"
 
const double PI = 3.14159265358979;
const ll INF =  1e18 + 7;
const ll MOD = 1e9 + 7;
const ll nax = 2505;
const int LOG = 25;


int getComponentSize(int src, int par, vector<int> adj[], vector<bool> &vis) { 
    vis[src] = true;
    int cnt = 1;

    for (int v : adj[src]) {
        if (v == par) continue;
        if (!vis[v]) {
            cnt += getComponentSize(v, src, adj, vis);
        }
    }

    return cnt;
}


void solve() {
    int n, m, c, r;
    cin >> n >> m >> c >> r;

    vector<int> adj[n + 1];
    vector<bool> vis(n + 1, false);

    
    for (int i = 1; i <= m; i++) {
        int x, y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    ll ans = 0;
    for (int i = 1; i <= n; i++) {
        if (!vis[i]) {
            int componentSize = getComponentSize(i, 0, adj, vis);
            if (r <= c) {
                ans = ans + 1LL * (componentSize - 1) * r + c;
            } else {
                ans = ans + 1LL * componentSize * c;
            }
        }
    }

    cout << ans << endl;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t; cin >> t; while(t--)
    solve();
    return 0;
}