#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...)
#endif

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    int N, M, Q;
    cin >> N >> M >> Q;
    assert(N <= 1000 && M <= 1000 && Q <= 5000);
    vector<int> A(N), W;
    for (int i = 0; i < N; i++) cin >> A[i];
    vector<vector<pair<int, int>>> G(N);
    for (int i = 0; i < M; i++) {
        int u, v, w;
        cin >> u >> v >> w, u--, v--;
        W.emplace_back(w);
        G[u].emplace_back(v, w);
        G[v].emplace_back(u, w);
    }

    ranges::sort(W);
    W.erase(ranges::unique(W).begin(), W.end());

    auto solve = [&](int s, int c) -> int {
        if (c == 1) return 0;  // 店 s 到達で ok
        int ok = ssize(W), ng = -1;
        while (ok - ng > 1) {
            int mid = midpoint(ok, ng);
            vector<int> seen(N);
            set<int> K;
            queue<int> que;
            seen[s] = true;
            K.emplace(A[s]);
            que.emplace(s);
            while (!que.empty()) {
                int v = que.front();
                que.pop();
                for (auto [u, w] : G[v]) {
                    if (seen[u] || W[mid] < w) continue;
                    seen[u] = true;
                    K.emplace(A[u]);
                    que.emplace(u);
                }
            }
            (ssize(K) >= c ? ok : ng) = mid;
        }
        return (ok == ssize(W) ? -1 : W[ok]);
    };

    while (Q--) {
        int s, c;
        cin >> s >> c, s--;
        cout << solve(s, c) << "\n";
    }
}