#include <bits/stdc++.h>

using namespace std;
using ll = long long;

const int MAXN = 1e5 + 10;

struct Edge {
  int v, w;
};

int n, a[MAXN];
ll dp[MAXN], cnt[MAXN], ans[MAXN];
vector<Edge> g[MAXN];

void dfs(int u, int fa) {
  cnt[u] = a[u];
  for (const auto [v, w] : g[u]) {
    if (v == fa) continue;
    dfs(v, u);
    dp[u] += dp[v] + abs(cnt[v]) * w;
    cnt[u] += cnt[v];
  }
}

void solve(int u, int fa) {
  for (const auto [v, w] : g[u]) {
    if (v == fa) continue;
    ans[v] = ans[u] + dp[u] - (abs(cnt[v]) * w << 1);
    solve(v, u);
  }
}

int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  cin >> n;
  for (int i = 1; i <= n; cin >> a[i++]);
  for (int i = 1, u, v, w; i < n; i++) {
    cin >> u >> v >> w;
    g[u].push_back({v, w});
    g[v].push_back({u, w});
  }
  dfs(1, 0);
  ans[1] = dp[1];
  solve(1, 0);
  cout << *min_element(ans + 1, ans + n + 1);
  return 0;
}

题目终于爬过来了