#include <bits/stdc++.h>
using namespace std;
vector<long long> p;
vector<long long> sz;
long long get_root(long long v) {
  if (p[v] == -1) {
    return v;
  }
  long long root = get_root(p[v]);
  p[v] = root;
  return root;
}
void unite(long long a, long long b) {
  a = get_root(a);
  b = get_root(b);
  if (a == b) {
    return;
  }
  if (sz[a] < sz[b]) {
    p[a] = b;
    sz[b] += sz[a];
  } else {
    p[b] = a;
    sz[a] += sz[b];
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  long long n, m, a, b, c;
  cin >> n;
  vector<vector<long long> > g;
  p.assign(n, -1);
  sz.assign(n, 1);
  vector<long long> n1(n, 0);
  vector<long long> f(n);
  for (long long i = 0; i < n; i++) cin >> f[i];
  cin >> m;
  for (long long i = 0; i < m; i++) {
    cin >> a >> b >> c;
    a--;
    b--;
    g.push_back({c, a, b});
  }
  sort(g.begin(), g.end());
  long long comp = n;
  long long ans = 0;
  for (auto i : g) {
    if (get_root(i[1]) == get_root(i[2]) || n1[i[2]] != 0 || comp == 1) {
      continue;
    }
    unite(i[1], i[2]);
    comp--;
    n1[i[2]] = 1;
    ans += i[0];
  }
  if (comp == 1)
    cout << ans;
  else
    cout << -1;
  return 0;
}
