output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N M K
      c_1 c_2 ... c_{N}
      a_1 b_1 w_1
      :
      a_M b_M w_M
attempt: #include "bits/stdc++.h"
  
  using namespace std;
  #ifdef _DEBUG
  #define _GLIBCXX_DEBUG
  #include "dump.hpp"
  #else
  #define dump(...)
  #endif
  
  #define int long long
  #define ll long long
  #define ll1 1ll
  #define ONE 1ll
  #define DBG 1
  #define rep(i, a, b) for (int i = (a); i < (b); i++)
  #define rrep(i, a, b) for (int i = (b)-1; i >= (a); i--)
  #define loop(n) rep(loop, (0), (n))
  #define all(c) begin(c), end(c)
  const int INF =
  sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
  const int MOD = (int)(1e9) + 7;
  const double PI = acos(-1);
  const double EPS = 1e-9;
  #define fi first
  #define se second
  #define pb push_back
  #define eb emplace_back
  using pii = pair<int, int>;
  // template<class T> ostream &operator<<(ostream &os,T &t){dump(t);return os;}
  template <typename T, typename S>
  istream &operator>>(istream &is, pair<T, S> &p) {
  	is >> p.first >> p.second;
  	return is;
  }
  template <typename T, typename S>
  ostream &operator<<(ostream &os, pair<T, S> &p) {
  	os << p.first << " " << p.second;
  	return os;
  }
  
  template <typename T> void printvv(const vector<vector<T>> &v) {
  	cerr << endl;
  	rep(i, 0, v.size()) rep(j, 0, v[i].size()) {
  		if (typeid(v[i][j]).name() == typeid(INF).name() and v[i][j] == INF) {
  			cerr << "INF";
  		}
  		else
  			cerr << v[i][j];
  		cerr << (j == v[i].size() - 1 ? '\n' : ' ');
  	}
  	cerr << endl;
  }
  /*
  typedef __int128_t Int;
  std::ostream &operator<<(std::ostream &dest, __int128_t value) {
  std::ostream::sentry s(dest);
    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 = '-';
  	}
  	int len = std::end(buffer) - d;
  	if (dest.rdbuf()->sputn(d, len) != len) {
  	  dest.setstate(std::ios_base::badbit);
  	}
    }
    return dest;
  }
  
  __int128 parse(string &s) {
    __int128 ret = 0;
    for (int i = 0; i < s.length(); i++)
  	if ('0' <= s[i] && s[i] <= '9')
  	  ret = 10 * ret + s[i] - '0';
    return ret;
  }
  */
  
  #ifndef _DEBUG
  #define printvv(...)
  #endif
  void YES(bool f) { cout << (f ? "YES" : "NO") << endl; }
  void Yes(bool f) { cout << (f ? "Yes" : "No") << endl; }
  template <class T> bool chmax(T &a, const T &b) {
  	if (a < b) {
  		a = b;
  		return true;
  	}
  	return false;
  }
  template <class T> bool chmin(T &a, const T &b) {
  	if (a > b) {
  		a = b;
  		return true;
  	}
  	return false;
  }
  using Weight = int;
  using Flow = int;
  struct Edge {
  	int s, d; Weight w; Flow c;
  	Edge() {};
  	Edge(int s, int d, Weight w = 1) : s(s), d(d), w(w), c(w) {};
  };
  bool operator<(const Edge &e1, const Edge &e2) { return e1.w < e2.w; }
  bool operator>(const Edge &e1, const Edge &e2) { return e2 < e1; }
  inline ostream &operator<<(ostream &os, const Edge &e) { return (os << '(' << e.s << ", " << e.d << ", " << e.w << ')'); }
  
  using Edges = vector<Edge>;
  using Graph = vector<Edges>;
  using Array = vector<Weight>;
  using Matrix = vector<Array>;
  
  void addArc(Graph &g, int s, int d, Weight w = 1) {
  	g[s].emplace_back(s, d, w);
  }
  void addEdge(Graph &g, int a, int b, Weight w = 1) {
  	addArc(g, a, b, w);
  	addArc(g, b, a, w);
  }
  struct DisjointSet {
  	// ２つのグループを１つにまとめる　と　2つの要素が同じグループに所属しているかどうかを判定する
  	vector<int> rank, p, S; // p->parent  S[findSet(v)] ->連結成分の大きさ
  	DisjointSet() {}
  	DisjointSet(int size) {
  		S.resize(size, 1);
  		rank.resize(size, 0);
  		p.resize(size, 0);
  		rep(i, 0, size) makeSet(i);
  	}
  	void makeSet(int x) {
  		p[x] = x;
  		rank[x] = 0;
  	}
  	bool same(int x, int y) { // 判定する
  		return findSet(x) == findSet(y);
  	}
  	void unite(int x, int y) { // 連結するときにはこれを使う
  		if (same(x, y))
  			return;
  		link(findSet(x), findSet(y));
  	}
  	void link(int x, int y) {
  		if (rank[x] > rank[y]) {
  			p[y] = x;
  		}
  		else {
  			p[x] = y;
  			if (rank[x] == rank[y]) {
  				rank[y]++;
  			}
  		}
  
  		S[x] = S[y] = S[x] + S[y];
  	}
  	int findSet(int x) {
  		if (x != p[x]) {
  			p[x] = findSet(p[x]); // path compression
  		}
  		return p[x];
  	}
  	int connectedComponentSize(int x) { return S[findSet(x)]; }
  };
  
  int kruskal(int N,int K, vector<Edge> &edges) {
  	int totalCost = 0;
  	sort(all(edges));
  	DisjointSet dset(N);
  	int k = 0;
  	rep(i, 0, edges.size()) {
  		Edge e = edges[i];
  		if (!dset.same(e.s, e.d)) {
  			totalCost += e.w;
  			dset.unite(e.s, e.d);
  			k++;
  			if (k == K - 1)break;
  		}
  	}
  	if (k != K - 1)totalCost = -1;
  	return totalCost;
  }
  
  signed main(signed argc, char *argv[]) {
  	cin.tie(0);
  	ios::sync_with_stdio(false);
  	cout << fixed << setprecision(12);
  
  	int N, M; cin >> N >> M;
  	int K; cin >> K;
  	vector<int>c(N);
  	int x = K;
  	rep(i, 0, N) {
  		cin >> c[i];
  		c[i]--;
  		if (c[i] == -1)c[i] = x++;
  	}
  
  	Edges es;
  	loop(M) {
  		int a, b, w; cin >> a >> b >> w;
  		a--, b--;
  		es.eb(c[a], c[b], w);
  	}
  	cout << kruskal(x,K, es) << endl;
  	return 0;
  }
  
problem_description: Statement
  
  Ringo has an undirected graph G with N vertices numbered 1,2,...,N and M edges
  numbered 1,2,...,M. Edge i connects Vertex a_{i} and b_{i} and has a length of
  w_i.
  
  Now, he is in the middle of painting these N vertices in K colors numbered
  1,2,...,K. Vertex i is already painted in Color c_i, except when c_i = 0, in
  which case Vertex i is not yet painted.
  
  After he paints each vertex that is not yet painted in one of the K colors, he
  will give G to Snuke.
  
  Based on G, Snuke will make another undirected graph G' with K vertices
  numbered 1,2,...,K and M edges. Initially, there is no edge in G'. The i-th
  edge will be added as follows:
  
    * Let x and y be the colors of the two vertices connected by Edge i in G.
    * Add an edge of length w_i connecting Vertex x and y in G'.
  
  What is the minimum possible sum of the lengths of the edges in the minimum
  spanning tree of G'? If G' will not be connected regardless of how Ringo
  paints the vertices, print -1.
samples: [{"input": "4 3 3\n    1 0 1 2\n    1 2 10\n    2 3 20\n    2 4 50", "output": "60\n    \n\nG' will only be connected when Vertex 2 is painted in Color 3.\n\n* * *"}, {"input": "5 2 4\n    0 0 0 0 0\n    1 2 10\n    2 3 10", "output": "-1\n    \n\nRegardless of how Ringo paints the vertices, two edges is not enough to\nconnect four vertices as one.\n\n* * *"}, {"input": "9 12 9\n    1 2 3 4 5 6 7 8 9\n    6 9 9\n    8 9 6\n    6 7 85\n    9 5 545631016\n    2 1 321545\n    1 6 33562944\n    7 3 84946329\n    9 7 15926167\n    4 7 53386480\n    5 8 70476\n    4 6 4549\n    4 8 8", "output": "118901402\n    \n\n* * *"}, {"input": "18 37 12\n    5 0 4 10 8 7 2 10 6 0 9 12 12 11 11 11 0 1\n    17 1 1\n    11 16 7575\n    11 15 9\n    10 10 289938980\n    5 10 17376\n    18 4 1866625\n    8 11 959154208\n    18 13 200\n    16 13 2\n    2 7 982223\n    12 12 9331\n    13 12 8861390\n    14 13 743\n    2 10 162440\n    2 4 981849\n    7 9 1\n    14 17 2800\n    2 7 7225452\n    3 7 85\n    5 17 4\n    2 13 1\n    10 3 45\n    1 15 973\n    14 7 56553306\n    16 17 70476\n    7 18 9\n    9 13 27911\n    18 14 7788322\n    11 11 8925\n    9 13 654295\n    2 10 9\n    10 1 545631016\n    3 4 5\n    17 12 1929\n    2 11 57\n    1 5 4\n    1 17 7807368", "output": "171"}]