#include <iostream>
#include <fstream>
#include <cmath>  
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <numeric>
#include <functional>
#include <string> 
#include <vector>
#include <bitset>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <random>

using namespace std;
using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll MOD2 = 998244353;
const ll LLINF = (ll)1e18;
const ll INTINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) { if (flg) { cout << hoge << endl; exit(0); } }
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) { o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o; }
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) { o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o; }
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) { o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o; }
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) { o << "{" << obj.first << ", " << obj.second << "}"; return o; }
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) { o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o; }
void print(void) { cout << endl; }
template <class Head> void print(Head&& head) { cout << head; print(); }
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) { cout << head << " "; print(forward<Tail>(tail)...); }
template <class T> void chmax(T& a, const T b) { a = max<T>(a, b); }
template <class T> void chmin(T& a, const T b) { a = min<T>(a, b); }
void YN(bool flg) { cout << ((flg) ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << ((flg) ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << ((flg) ? "yes" : "no") << endl; }

class Union_Find_Tree {
public:
	vector<int> parent;
	vector<int> rank;

	Union_Find_Tree(int N = 1) : parent(N), rank(N, 0) {
		for (int i = 0; i < N; ++i) parent[i] = i;
	}

	int root(int n) {
		return (parent[n] == n ? n : parent[n] = root(parent[n]));
	}

	bool same(int n, int m) {
		return root(n) == root(m);
	}

	void unite(int n, int m) {
		n = root(n);
		m = root(m);
		if (n == m) return;
		if (rank[n]<rank[m]) {
			parent[n] = m;
		}
		else {
			parent[m] = n;
			if (rank[n] == rank[m]) rank[n]++;
		}
	}
};

int main() {
	int N, M, K;
	cin >> N >> M >> K;
	V<ll> c(N),d(K+1,0),u(M),v(M),w(M);
	for (int i = 0; i < N; ++i) cin >> c[i];
	for (int i = 0; i < M; ++i) cin >> u[i] >> v[i] >> w[i];
	for (int i = 0; i < M; ++i) u[i]--, v[i]--;
	Union_Find_Tree uf(N + K);
	for (int i = 0; i < N; ++i) if (c[i]) uf.unite(i, N - 1 + c[i]);
	V<P<ll, int>> ord(M);
	for (int i = 0; i < M; ++i) ord[i] = { w[i],i };
	sort(ALL(ord));

	ll ans = 0;
	K--;
	for (int i = 0; i < M; ++i) {
		if (K == 0) break;
		int idx = ord[i].second;
		if (uf.same(u[idx], v[idx])) continue;
		uf.unite(u[idx], v[idx]);
		K--;
		ans += w[idx];
	}
	cout << (K?-1:ans) << endl;

	return 0;
}



Measured memory_bytes: 7296