#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = std::int_fast64_t;
using std::cerr;
using std::cin;
using std::cout;
using std::endl;

#if defined(DONLINE_JUDGE)
#define NDEBUG
#elif defined(ONLINE_JUDGE)
#define NDEBUG
#endif

template <typename T>
std::vector<T> make_v(size_t a) {
    return std::vector<T>(a);
}
template <typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return std::vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

int main() {
    int n, k, m, p;
    scanf("%d%d%d%d", &n, &k, &m, &p);
    std::vector<std::vector<int>> g(n);
    for (int i = 0; i < m; ++i) {
        int a, b;
        scanf("%d%d", &a, &b);
        --a;
        --b;

        g[a].push_back(b);
        g[b].push_back(a);
    }
    std::vector<int> s(n);
    for (auto& v : s) scanf("%d", &v);

    using P = std::pair<int, int>;  // (time, vertex)
    std::priority_queue<P, std::vector<P>, std::greater<P>> qu;

    std::vector<int> imm(n, -1);
    for (int i = 0; i < k; ++i) {
        int x;
        scanf("%d", &x);
        --x;

        imm[x] = p;
        qu.push({s[x], x});
    }

    std::vector<int> ban(n, -1);
    while (!qu.empty()) {
        const auto [now, v] = qu.top();
        qu.pop();
        if (ban[v] != -1 and ban[v] < now) continue;

        for (int to : g[v]) {
            if (imm[to] == -1) {
                imm[to] = now + p;
            } else if (now < imm[to]) {
                imm[to] = 0;
                ban[to] = now;
                continue;
            } else if (imm[to] <= now) {
                continue;
            }

            qu.push({now + s[to], to});
        }
    }

    const int ans = std::count(ban.begin(), ban.end(), -1);
    printf("%d\n", n - ans);
    return 0;
}