#include <bits/stdc++.h>

using namespace std;
using ll = long long;
// #define int ll
using PII = pair<ll, ll>;

#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()

template<typename T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = max(a, b); }
template<typename T> bool IN(T a, T b, T x) { return a<=x&&x<b; }
template<typename T> T ceil(T a, T b) { return a/b + !!(a%b); }

template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) {
    return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type
fill_v(T &t, const V &v) { t=v; }
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type
fill_v(T &t, const V &v ) { for(auto &e:t) fill_v(e,v); }

template<class S,class T>
ostream &operator <<(ostream& out,const pair<S,T>& a) {
    out<<'('<<a.first<<','<<a.second<<')'; return out;
}
template<class T>
ostream &operator <<(ostream& out,const vector<T>& a){
    out<<'[';
    for(const T &i: a) out<<i<<',';
    out<<']';
    return out;
}
template<class T>
ostream &operator <<(ostream& out, const set<T>& a) {
    out<<'{';
    for(const T &i: a) out<<i<<',';
    out<<'}';
    return out;
}
template<class T, class S>
ostream &operator <<(ostream& out, const map<T,S>& a) {
    out<<'{';
    for(auto &i: a) out<<i<<',';
    out<<'}';
    return out;
}

int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0}; // DRUL
const int INF = 1<<30;
const ll LLINF = 1LL<<60;
const ll MOD = 1000000007;

struct UnionFind {
    vector<int> par, s;
    UnionFind(int n=2e5) { init(n); }
    void init(int n) {
        s.assign(n, 1); par.resize(n);
        iota(par.begin(), par.end(), 0);
    }
    int find(int x) {
        if(par[x] == x) return x;
        return par[x] = find(par[x]);
    }
    void unite(int x, int y) {
        x = find(x);
        y = find(y);
        if(x == y) return;
        if(s[x] < s[y]) par[x] = y, s[y] = s[x] + s[y];
        else par[y] = x, s[x] = s[x] + s[y];
    }
    bool same(int x, int y) { return find(x) == find(y); }
    int size(int x) { return s[find(x)]; }
};

signed main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll n, m, k;
    cin >> n >> m >> k;
    vector<ll> c(n);
    REP(i, n) cin >> c[i];
    vector<vector<ll>> v(k);
    REP(i, n) if(c[i]>=1) v[c[i]-1].push_back(i);

    vector<ll> a(m), b(m), w(m);
    REP(i, m) {
        cin >> a[i] >> b[i] >> w[i];
        a[i]--, b[i]--;
    }
    REP(i, k) FOR(j, 1, v[i].size()) {
        a.push_back(v[i][j-1]);
        b.push_back(v[i][j]);
        w.push_back(0);
        ++m;
    }

    vector<ll> idx(m);
    iota(ALL(idx), 0);
    sort(ALL(idx), [&](ll l, ll r){
        return w[l] < w[r];
    });

    UnionFind uf(n);
    ll ret = 0, cnt = 0;
    for(auto i: idx) {
        if(uf.same(a[i], b[i]) || cnt >= k-1) continue;
        uf.unite(a[i], b[i]);
        ret += w[i];
        if(w[i] != 0) cnt++;
    }

    if(cnt == k-1) cout << ret << endl;
    else cout << -1 << endl;

    return 0;
}


Measured memory_bytes: 10576