#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <numeric>
#include <tuple>
#include <stack>

template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
  if (lhs > rhs) {
    lhs = rhs;
    return true;
  }
  return false;
}

template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
  if (lhs < rhs) {
    lhs = rhs;
    return true;
  }
  return false;
}

// [l, r) from l to r
struct range {
  struct itr {
    int i;
    constexpr itr(int i_): i(i_) { }
    constexpr void operator ++ () { ++i; }
    constexpr int operator * () const { return i; }
    constexpr bool operator != (itr x) const { return i != x.i; }
  };
  const itr l, r;
  constexpr range(int l_, int r_): l(l_), r(std::max(l_, r_)) { }
  constexpr itr begin() const { return l; }
  constexpr itr end() const { return r; }
};

// [l, r) from r to l
struct revrange {
  struct itr {
    int i;
    constexpr itr(int i_): i(i_) { }
    constexpr void operator ++ () { --i; }
    constexpr int operator * () const { return i; }
    constexpr bool operator != (itr x) const { return i != x.i; }
  };
  const itr r, l;
  constexpr revrange(int l_, int r_): l(l_ - 1), r(std::max(l_, r_) - 1) { }
  constexpr itr begin() const { return r; }
  constexpr itr end() const { return l; }
};

class union_find {
private:
  int component;
  std::vector<int> parent;

public:
  union_find() = default;
  union_find(int size_) { init(size_); }

  void init(int size_) {
    component = size_;
    parent.assign(size_, -1);
  }

  int count_components() const { 
    return component; 
  }
  int component_size(int i) { 
    return -parent[find_parent(i)]; 
  }
  bool same_component(int i, int j) { 
    return find_parent(i) == find_parent(j); 
  }

  int find_parent(int i) {
    if (parent[i] < 0) {
      return i;
    }
    else {
      return parent[i] = find_parent(parent[i]);
    }
  }

  bool unite(int i, int j) {
    i = find_parent(i);
    j = find_parent(j);
    if (i == j) {
      return false;
    }
    if (parent[i] > parent[j]) {
      std::swap(i, j);
    }
    parent[i] += parent[j];
    parent[j] = i;
    --component;
    return true;
  }

};

int main() {
  int N, M, K;
  std::cin >> N >> M >> K;
  std::vector<int> col(N);
  std::vector<bool> appeared(N);
  for (int &x: col) {
    std::cin >> x;
    --x;
    if (x != -1) {
      appeared[x] = true;
    }
  }
  int now = 0;
  for (int &x: col) {
    if (x == -1) {
      while (appeared[now]) {
        ++now;
      }
      x = now;
      appeared[now] = true;
    }
  }
  std::vector<std::tuple<int, int, int>> edges;
  for (int i: range(0, M)) {
    int a, b, w;
    std::cin >> a >> b >> w;
    edges.emplace_back(w, col[a - 1], col[b - 1]);
  }
  std::sort(edges.begin(), edges.end());
  long long ans = 0;
  std::stack<int> used;
  union_find dsu(N);
  for (int i: range(0, M)) {
    int w, a, b;
    std::tie(w, a, b) = edges[i];
    if (dsu.unite(a, b)) {
      used.push(w);
      ans += w;
    }
  }
  if (used.size() < K - 1) {
    std::cout << "-1\n";
    return 0;
  }
  while (used.size() >= K) {
    ans -= used.top();
    used.pop();
  }
  std::cout << ans << '\n';
  return 0;
}


Measured memory_bytes: 2676