#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int>> v[100001];
int visited[100001] = {0};
int ct = 0;
long long int power(long long int a, long long int b, long long int mod) {
  a %= mod;
  long long int res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return res;
}
int sum = 0;
int dfs(int x, int a[]) {
  for (auto y : v[x]) {
    if (a[x] < a[y.second]) {
      visited[x] = 1;
      sum += y.first;
      return 1;
    }
  }
  return 0;
}
int main() {
  int n, i, x, y;
  cin >> n;
  int a[n];
  for (i = 0; i < n; i++) cin >> a[i];
  int q;
  cin >> q;
  set<int> s;
  while (q--) {
    int ii;
    cin >> x >> y >> ii;
    x -= 1;
    y -= 1;
    s.insert(y);
    v[y].push_back({ii, x});
  }
  for (auto x : s) {
    sort(v[x].begin(), v[x].end());
    if (!dfs(x, a)) {
      cout << -1;
      return 0;
    }
  }
  int cnt = 0;
  for (i = 0; i < n; i++) {
    if (visited[i] == 0) {
      cnt += 1;
    }
    if (cnt > 1) {
      cout << -1;
      return 0;
    }
  }
  if (cnt == 1)
    cout << sum;
  else
    cout << -1;
}
