#include <bits/stdc++.h>
using namespace std;
template <typename T>
void dprintln(const T &t) {
  cout << t << endl;
}
template <typename T, typename... Args>
void dprintln(const T &t, const Args &...rest) {
  cout << t << ' ';
  dprintln(rest...);
}
template <typename T>
void println(const T &t) {
  cout << t << '\n';
}
template <typename T, typename... Args>
void println(const T &t, const Args &...rest) {
  cout << t << ' ';
  println(rest...);
}
template <typename T>
void print(const T &t) {
  cout << t << ' ';
}
template <typename T, typename... Args>
void print(const T &t, const Args &...rest) {
  cout << t;
  print(rest...);
}
template <class T>
void scan(T &t) {
  cin >> t;
}
template <class T, class... Args>
void scan(T &a, Args &...rest) {
  cin >> a;
  scan(rest...);
}
using ll = long long;
using vl = vector<ll>;
using vi = vector<int>;
using pii = pair<int, int>;
using vb = vector<bool>;
using vpii = vector<pii>;
template <typename T>
struct bit {
  vector<T> a;
  explicit bit(int n, int v = 0) {
    a.resize(n + 1);
    if (v != 0) {
      for (int i = 1; i <= n; ++i) a[i] = v;
    }
  }
  T sum(T x) {
    T res = 0;
    while (x) {
      res += a[x];
      x -= x & -x;
    }
    return res;
  }
  T sum(int l, int r) {
    if (l > r) return 0;
    return sum(r) - sum(l - 1);
  }
  void add(int x, T v) {
    while (x < a.size()) {
      a[x] += v;
      x += x & -x;
    }
  }
  void clear() { fill(a.begin(), a.end(), 0); }
};
vi get_prime(int n) {
  vi minp(n + 1), p;
  for (int i = 2; i <= n; i++) {
    if (!minp[i]) {
      minp[i] = i;
      p.push_back(i);
    }
    for (auto &x : p) {
      if (x <= minp[i] && x * i <= n)
        minp[x * i] = x;
      else
        break;
    }
  }
  return p;
}
const int mod = 1000000007;
inline void add_mod(ll &x, const ll &y) {
  x += y;
  if (x >= mod) x -= mod;
}
void sub_mod(ll &x, const ll &y) {
  x -= y;
  if (x < 0) x += mod;
}
template <typename T>
using vv = vector<vector<T>>;
template <typename T1, typename T2 = T1>
using vp = vector<pair<T1, T2>>;
template <typename T, int n>
using va = vector<array<T, n>>;
using vec = vector<ll>;
using mat = vector<vec>;
mat get_I(int n) {
  mat res(n, vec(n));
  for (int i = 0; i < n; i++) res[i][i] = 1;
  return res;
}
mat operator*(const mat &a, const mat &b) {
  mat c(a.size(), vec(b[0].size()));
  for (size_t i = 0; i < a.size(); i++) {
    for (size_t j = 0; j < a[0].size(); j++) {
      if (a[i][j]) {
        for (size_t k = 0; k < b[0].size(); k++) {
          add_mod(c[i][k], a[i][j] * b[j][k] % mod);
        }
      }
    }
  }
  return c;
}
vec operator*(const mat &a, const vec &b) {
  vec c(a.size());
  for (size_t i = 0; i < a.size(); i++) {
    for (size_t j = 0; j < a[0].size(); j++) {
      add_mod(c[i], a[i][j] * b[j] % mod);
    }
  }
  return c;
}
mat pow(mat a, ll n) {
  mat res(a.size(), vec(a[0].size()));
  for (size_t i = 0; i < a.size(); i++) {
    res[i][i] = 1;
  }
  while (n) {
    if (n & 1) {
      res = res * a;
    }
    a = a * a;
    n >>= 1;
  }
  return res;
}
struct UF {
  vi par;
  explicit UF(int n) {
    par.assign(n + 1, 0);
    for (int i = (1); i < (n + 1); ++i) par[i] = i;
  }
  int find(int x) { return x == par[x] ? x : par[x] = find(par[x]); }
  void unite(int x, int y) { par[find(x)] = find(y); }
};
vi get_popcnt(int n) {
  vi res(n + 1);
  for (int i = (0); i < (n); ++i) {
    if (i * 2 <= n) res[i * 2] = res[i];
    if ((i & 1) == 0) res[i + 1] = res[i] + 1;
  }
  return res;
}
const int N = 3e5 + 5, M = 1005;
vv<pii> g(N);
ll w[N];
ll up1[N], up2[N];
int from[N];
void dfs(int u, int f) {
  up1[u] = up2[u] = w[u];
  from[u] = 0;
  for (auto &e : g[u]) {
    int v = e.first, l = e.second;
    if (v != f) {
      dfs(v, u);
      if (up1[v] >= l) {
        auto t = up1[v] - l + w[u];
        if (t > up1[u]) {
          up2[u] = up1[u];
          up1[u] = t;
          from[u] = v;
        } else if (t > up2[u]) {
          up2[u] = t;
        }
      }
    }
  }
}
ll ans = 0;
void dfs2(int u, int f, ll ma) {
  ans = max(ans, max(ma, up1[u]));
  if (ma >= up1[u]) {
    for (auto &e : g[u]) {
      int v = e.first, l = e.second;
      if (v != f) {
        dfs2(v, u, max(ma - l, 0LL) + w[v]);
      }
    }
  } else {
    for (auto &e : g[u]) {
      int v = e.first, l = e.second;
      if (v != f) {
        ll t = v == from[u] ? max(ma, up2[u]) : up1[u];
        dfs2(v, u, max(t - l, 0LL) + w[v]);
      }
    }
  }
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  for (int i = (1); i < (n + 1); ++i) cin >> w[i];
  for (int _ = 0, __ = (int)n - 1; _ < __; _++) {
    int u, v, w;
    scan(u, v, w);
    g[u].emplace_back(v, w), g[v].emplace_back(u, w);
  }
  dfs(1, 1);
  dfs2(1, 1, w[1]);
  println(ans);
  return 0;
}
