#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cstring>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <numeric>
#include <utility>
#include <iomanip>
#include <algorithm>
#include <functional>
using namespace std;

#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl
#define EACH(i, s) for (__typeof__((s).begin()) i = (s).begin(); i != (s).end(); ++i)

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T1, class T2> ostream& operator << (ostream &s, pair<T1,T2> P)
{ return s << '<' << P.first << ", " << P.second << '>'; }
template<class T> ostream& operator << (ostream &s, vector<T> P)
{ for (int i = 0; i < P.size(); ++i) { if (i > 0) { s << " "; } s << P[i]; } return s; }
template<class T> ostream& operator << (ostream &s, vector<vector<T> > P)
{ for (int i = 0; i < P.size(); ++i) { s << endl << P[i]; } return s << endl; }
template<class T1, class T2> ostream& operator << (ostream &s, map<T1,T2> P)
{ EACH(it, P) { s << "<" << it->first << "->" << it->second << "> "; } return s << endl; }


const int MAX = 210000;
const int MAX_UF = MAX;
struct UnionFind {
    int size_;
    int par[MAX_UF];
    int rank[MAX_UF];
    int weight[MAX_UF];
    
    UnionFind(int n = 0) {size_ = n; for (int i = 0; i < n; ++i) par[i] = i, rank[i] = 0;}
    void init(int n) {size_ = n; for (int i = 0; i < n; ++i) par[i] = i, rank[i] = 0, weight[i] = -1;}
    int root(int x) {return par[x] == x ? x : par[x] = root(par[x]);}
    bool same(int x, int y) {return root(x) == root(y);}
    int get(int x) { return weight[root(x)]; }
    void set(int x, int w) { weight[root(x)] = w; }
    friend ostream& operator << (ostream& s, UnionFind uf) {
        vector<vector<int> > res = uf.group();
        for (int i = 0; i < res.size(); ++i) { s << uf.get(res[i][0]) << ", " << res[i]; }
        return s;
    }
    
    void connect(int x, int y) {
        x = root(x); y = root(y);
        if (x == y) return;
        if (rank[x] < rank[y]) par[x] = y;
        else {par[y] = x; if (rank[x] == rank[y]) ++rank[x];}
    }
    
    vector<vector<int> > group() {
        vector<vector<int> > res;
        vector<bool> fixed(size_, false);
        for (int i = 0; i < size_; ++i) {
            if (!fixed[i]) {
                vector<int> temp;
                for (int j = i; j < size_; ++j) {
                    if (same(i, j)) temp.push_back(j), fixed[j] = true;
                }
                res.push_back(temp);
            }
        }
        return res;
    }
} uf;

int N, M, K;
typedef pair<int,int> pint;
typedef pair<long long, pint> Edge;
vector<Edge> G;
int C[MAX];

map<int,int> ma;

int main() {
    while (cin >> N >> M >> K) {
        for (int i = 0; i < N; ++i) cin >> C[i];
        G.clear();
        ma.clear();
        
        int iter = K;
        for (int i = 0; i < M; ++i) {
            int a, b, w;
            cin >> a >> b >> w;
            --a, --b;
            int ua, ub;
            
            if (C[a] != 0) ua = C[a] - 1;
            else if (ma.count(a)) ua = ma[a];
            else {
                ua = iter;
                ma[a] = iter++;
            }
            
            if (C[b] != 0) ub = C[b] - 1;
            else if (ma.count(b)) ub = ma[b];
            else {
                ub = iter;
                ma[b] = iter++;
            }
            
            G.push_back(Edge(w, pint(ua, ub)));
        }
        
        sort(G.begin(), G.end());
        uf.init(N+K);
        
        //COUT(G);
        
        int con = 0;
        long long res = 0;
        for (auto e : G) {
            int u = e.second.first;
            int v = e.second.second;
            long long w = e.first;
            
            if (uf.same(u, v)) continue;
            uf.connect(u, v);
            ++con;
            res += w;
            
            if (con == K - 1) break;
        }
        
        if (con >= K - 1) cout << res << endl;
        else cout << -1 << endl;
    }
}















Measured memory_bytes: 9200