#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const int nax = 3e5 + 10;
long long w[nax];
long long dp[nax], ans;
vector<pair<int, long long> > v[nax];
void dfs(int id, int par) {
  vector<long long> temp;
  for (auto i : v[id]) {
    if (i.first == par) continue;
    dfs(i.first, id);
    temp.emplace_back(dp[i.first] - i.second);
    dp[id] = max(dp[id], dp[i.first] - i.second);
  }
  dp[id] += w[id];
  ans = max(ans, dp[id]);
  sort(temp.begin(), temp.end());
  reverse(temp.begin(), temp.end());
  if ((int)temp.size() == 1) ans = max(ans, temp[0] + w[id]);
  if ((int)temp.size() > 1) ans = max(ans, temp[1] + temp[0] + w[id]);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  for (int i = 1; i <= n; ++i) cin >> w[i];
  for (int i = 0; i < n - 1; ++i) {
    int x, y, t;
    cin >> x >> y >> t;
    v[x].emplace_back(y, t);
    v[y].emplace_back(x, t);
  }
  dfs(1, -1);
  cout << ans << '\n';
  ;
  return 0;
}
