#include <bits/stdc++.h>
using namespace std;
int n, a[200005];
void slove() {
  int temp, u, v, w, m;
  for (int i = 1; i <= n; i++) cin >> temp, a[i] = 0x3f3f3f3f;
  cin >> m;
  for (int i = 1; i <= m; i++) {
    cin >> u >> v >> w;
    if (a[v] > w) a[v] = w;
  }
  int flag = 1, k = 1;
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    if (a[i] == 0x3f3f3f3f && k) {
      ans -= 0x3f3f3f3f;
      k = 0;
    } else if (a[i] == 0x3f3f3f3f) {
      flag = 0;
      break;
    }
    ans += a[i];
  }
  if (flag)
    cout << ans << '\n';
  else
    cout << -1 << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  slove();
  return 0;
}
