#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif

using namespace std;

typedef long long ll;
#define all(x) begin(x), end(x)
constexpr int INF = (1 << 30) - 1;
constexpr long long IINF = (1LL << 60) - 1;
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

template <class T> istream& operator>>(istream& is, vector<T>& v) {
    for (auto& x : v) is >> x;
    return is;
}

template <class T> ostream& operator<<(ostream& os, const vector<T>& v) {
    auto sep = "";
    for (const auto& x : v) os << exchange(sep, " ") << x;
    return os;
}

template <class T, class U = T> bool chmin(T& x, U&& y) { return y < x and (x = forward<U>(y), true); }

template <class T, class U = T> bool chmax(T& x, U&& y) { return x < y and (x = forward<U>(y), true); }

template <class T> void mkuni(vector<T>& v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}

template <class T> int lwb(const vector<T>& v, const T& x) { return lower_bound(begin(v), end(v), x) - begin(v); }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, K, M, P;
    cin >> N >> K >> M >> P;
    vector<vector<int>> G(N);
    for (; M--;) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        G[u].emplace_back(v);
        G[v].emplace_back(u);
    }
    vector<int> s(N);
    cin >> s;
    vector<int> x(K);
    for (int& val : x) cin >> val, val--;

    vector<bool> quarantine(N, false), immune(N, false);
    vector<int> cnt(N, 0);
    /*
    0 : 回復
    1 : 感染
    */
    priority_queue<tuple<int, int, int, int>, vector<tuple<int, int, int, int>>, greater<tuple<int, int, int, int>>>
        pq;  // (時刻、イベント、対象者、感染源)
    for (int& val : x) pq.emplace(0, 1, val, -1);
    while (not pq.empty()) {
        auto [time, event, idx, from] = pq.top();
        pq.pop();
        if (quarantine[idx]) continue;
        if (event == 0) {
            immune[idx] = true;
        } else {
            if (immune[idx]) continue;
            if (from != -1 and quarantine[from]) continue;
            if (++cnt[idx] == 2) {
                quarantine[idx] = true;
                continue;
            }
            pq.emplace(time + P, 0, idx, -1);
            for (int& adj : G[idx]) pq.emplace(time + s[idx], 1, adj, idx);
        }
    }

    int ans = 0;
    for (int i = 0; i < N; i++) {
        if (quarantine[i]) {
            ans++;
        }
    }
    cout << ans << '\n';
    return 0;
}