#include <bits/stdc++.h>
// #include <boost/multiprecision/cpp_int.hpp>
using namespace std;
using std::cerr, std::cin, std::cout;
#define vec vector
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using mint = atcoder::modint998244353;
std::istream &operator>>(std::istream &is, mint &a) {
	long long t;
	is >> t;
	a = t;
	return is;
}
std::ostream &operator<<(std::ostream &os, mint a) { return os << a.val(); }
// vec<mint> operator*(const vec<mint> &a, const vec<mint> &b) { return a.empty() || b.empty() ? vec<mint>() : atcoder::convolution(a, b); }
// vec<mint> &operator*=(vec<mint> &a, const vec<mint> &b) { return a = a * b; }
#endif
typedef long double ld;
#if LONG_MAX == 2147483647L
#undef long
#define long long long
#endif
#define uint unsigned int
#define ulong unsigned long
#define overload3(a, b, c, name, ...) name
#define rep3(i, a, b) for (int i = (a); i < (b); i++)
#define rep2(i, n) rep3(i, 0, n)
#define rep1(n) rep2(__i__, n)
#define rep(...) overload3(__VA_ARGS__, rep3, rep2, rep1)(__VA_ARGS__)
#define per3(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define per2(i, n) per3(i, 0, n)
#define per1(n) per2(__i__, n)
#define per(...) overload3(__VA_ARGS__, per3, per2, per1)(__VA_ARGS__)
#define all(a) a.begin(), a.end()
#define UNIQUE(a) sort(all(a)), a.erase(unique(all(a)), a.end()), a.shrink_to_fit()
#define sz(a) static_cast<int>(a.size())
#ifndef DEBUG
#define cerr \
	if (false) cerr
// #undef assert
// #define assert(...) void(0)
#undef endl
#define endl '\n'
#endif
ostream &operator<<(ostream &os, __int128_t value) {
	ostream::sentry s(os);
	if (s) {
		__uint128_t tmp = value < 0 ? -value : value;
		char buffer[128];
		char *d = std::end(buffer);
		do {
			--d;
			*d = "0123456789"[tmp % 10];
			tmp /= 10;
		} while (tmp != 0);
		if (value < 0) --d, *d = '-';
		const int len = std::end(buffer) - d;
		if (os.rdbuf()->sputn(d, len) != len) os.setstate(std::ios_base::badbit);
	}
	return os;
}
template <typename T, typename S>
ostream &operator<<(ostream &os, pair<T, S> a) {
	return os << a.first << ' ' << a.second;
};
template <typename T>
ostream &operator<<(ostream &os, vector<T> a) {
	const int n = a.size();
	rep(i, n) {
		os << a[i];
		if (i + 1 != n) os << " ";
	}
	return os;
}
template <typename T, typename S>
istream &operator>>(istream &is, pair<T, S> &a) {
	return is >> a.first >> a.second;
}
template <typename T, size_t n>
ostream &operator<<(ostream &os, array<T, n> a) {
	rep(i, n) {
		os << a[i];
		if (i + 1 != n) os << " ";
	}
	return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &a) {
	for (T &i : a) is >> i;
	return is;
}
template <typename T, typename S>
bool chmin(T &x, S y) {
	if ((T)y < x) {
		x = (T)y;
		return true;
	}
	return false;
}
template <typename T, typename S>
bool chmax(T &x, S y) {
	if (x < (T)y) {
		x = (T)y;
		return true;
	}
	return false;
}
template <typename T>
void operator++(vector<T> &a) {
	for (T &i : a) ++i;
}
template <typename T>
void operator--(vector<T> &a) {
	for (T &i : a) --i;
}
template <typename T>
void operator++(vector<T> &a, int) {
	for (T &i : a) i++;
}
template <typename T>
void operator--(vector<T> &a, int) {
	for (T &i : a) i--;
}
void init(), solve();
int main() {
	// srand((unsigned)time(NULL));
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout << fixed << setprecision(20);
	cerr << fixed << setprecision(20);
	init();
	int t = 1;
	// cin >> t;
	while (t--) solve();
}
void init() {}
void solve() {
	int n, m, q;
	cin >> n >> m >> q;
	vec<int> a(n);
	cin >> a;
	vec<tuple<int, int, long>> g(m);
	for (auto &[u, v, w] : g) {
		cin >> u >> v >> w;
		u--, v--;
	}
	sort(all(g), [](const tuple<int, int, long> &s1, const tuple<int, int, long> &s2) { return get<2>(s1) < get<2>(s2); });
	vec<int> p(2 * n, -1), cnt(2 * n, 1), root(n);
	vec<long> w(2 * n);
	rep(i, n) root[i] = i;
	vec<unordered_set<int>> d(n);
	rep(i, n) d[i].insert(a[i]);
	atcoder::dsu dsu(n);
	int k = n;
	for (auto [u, v, cost] : g) {
		u = dsu.leader(u), v = dsu.leader(v);
		if (u == v) continue;
		const int x = root[u], y = root[v];
		p[x] = p[y] = k;
		w[k] = cost;
		if (sz(d[u]) > sz(d[v])) swap(u, v);
		d[v].merge(d[u]);
		d[u].clear();
		const int r = dsu.merge(u, v);
		if (r == u) swap(d[u], d[v]);
		root[r] = k;
		cnt[k] = sz(d[r]);
		k++;
	}
	vec<int> rt(n);
	rep(i, n) rt[i] = root[dsu.leader(i)];
	const int LOG = bit_width((unsigned)k);
	vec<vec<int>> up(LOG, vec<int>(k, -1));
	rep(i, k) up[0][i] = p[i];
	rep(j, 1, LOG) rep(i, k) if (up[j - 1][i] != -1) up[j][i] = up[j - 1][up[j - 1][i]];
	while (q--) {
		int s, c;
		cin >> s >> c;
		s--;
		if (cnt[rt[s]] < c) {
			cout << -1 << endl;
			continue;
		}
		if (c <= 1) {
			cout << 0 << endl;
			continue;
		}
		int x = s;
		per(j, LOG) {
			const int y = up[j][x];
			if (y != -1 && cnt[y] < c) x = y;
		}
		cout << w[p[x]] << endl;
	}
}