#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 69;
const int64_t INF = 100000000000000018LL;
long long p[N], n, szz[N], m, k;
void make(long long n) {
  for (long long i = 1; i <= n; i++) {
    p[i] = i;
    szz[i] = 1;
  }
  return;
}
long long find(long long x) {
  if (p[x] == x) return x;
  return p[x] = find(p[x]);
}
long long merge(long long a, long long b) {
  long long x = find(a);
  long long y = find(b);
  if (x != y) {
    if (szz[x] < szz[y]) swap(x, y);
    p[y] = x;
    szz[x] += szz[y];
    return 1;
  }
  return 0;
}
void solve() {
  long long n;
  cin >> n;
  long long a[n + 1], i;
  for (i = 1; i <= n; i++) cin >> a[i];
  vector<pair<long long, pair<long long, long long>>> v;
  long long m, x, y, z;
  cin >> m;
  for (i = 1; i <= m; i++) {
    cin >> x >> y >> z;
    v.push_back({z, {x, y}});
  }
  make(n);
  sort((v).begin(), (v).end());
  set<long long> s;
  long long ans = 0, cnt = 0;
  for (i = 0; i < (long long)v.size(); i++) {
    x = v[i].second.first;
    y = v[i].second.second;
    z = v[i].first;
    if (cnt != n - 1) {
      if (a[x] > a[y]) {
        if (find(x) != find(y) && s.count(y) == 0) {
          merge(x, y);
          s.insert(y);
          ans += z;
          cnt++;
        }
      }
    }
  }
  if (cnt != n - 1)
    cout << -1;
  else
    cout << ans;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  while (t--) {
    solve();
  }
}
