#include <bits/stdc++.h>
#include <atcoder/dsu>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
template <class T> void dedup(vector<T>& a) {
    sort(a.begin(), a.end());
    a.erase(unique(a.begin(), a.end()), a.end());
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, M, Q;
    cin >> N >> M >> Q;
    vector<int> A(N);
    rep(i, N) cin >> A[i];
    vector<array<ll, 3>> ES;
    rep(i, M) {
        int a, b, c;
        cin >> a >> b >> c;
        a--, b--;
        ES.push_back({c, a, b});
    }
    vector<int> V(Q), U(Q);
    rep(i, Q) {
        cin >> V[i] >> U[i];
        V[i]--;
    }
    vector<int> ANS(Q, -1);
    sort(ES.begin(), ES.end());
    atcoder::dsu uf(N);
    vector<vector<int>> S(N);
    using TT = pair<int, int>;
    vector<priority_queue<TT, vector<TT>, std::greater<>>> T(N);
    rep(i, N) S[i].push_back(A[i]);
    rep(i, Q) {
        if (U[i] == 1) ANS[i] = 0;
        else {
            T[V[i]].push({U[i], i});
        }
    }
    for (auto [c, a, b] : ES) {
        a = uf.leader(a), b = uf.leader(b);
        if (a == b) continue;
        int n = uf.merge(a, b);
        int o = n ^ a ^ b;
        if (S[n].size() < S[o].size()) swap(S[n], S[o]);
        rep(i, S[o].size()) S[n].push_back(S[o][i]);
        if (T[n].size() < T[o].size()) swap(T[n], T[o]);
        while (T[o].size()) T[n].push(T[o].top()), T[o].pop();
        S[o].clear();
        dedup(S[n]);
        int s = S[n].size();
        while (T[n].size() && T[n].top().first <= s) {
            ANS[T[n].top().second] = c;
            T[n].pop();
        }
    }
    rep(i, Q) cout << ANS[i] << "\n";
}