#include <bits/stdc++.h>
using namespace std;
const int inf = 1000000000;
int sz[50005], f[50005], b[50005];
int sum;
pair<int, pair<int, int> > a[5005];
bool isOk;
int n;
int find_set(int x) {
  if (f[x] == x) return x;
  f[x] = find_set(f[x]);
  return f[x];
}
void unite(int x, int y) {
  x = find_set(x);
  y = find_set(y);
  if (x == y) return;
  f[x] = y;
  b[y] += b[x];
  sz[y] += sz[x];
  if (sz[y] > sum - b[y]) isOk = false;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n - 1; ++i) {
    scanf("%d%d%d", &a[i].second.first, &a[i].second.second, &a[i].first);
    a[i].second.first--;
    a[i].second.second--;
  }
  sort(a, a + n - 1);
  for (int i = 0; i < n; ++i) {
    scanf("%d", &b[i]);
    sum += b[i];
    sz[i] = 1;
  }
  for (int i = 0; i < n; ++i) f[i] = i;
  isOk = true;
  int ans = a[0].first;
  for (int i = 0; i < n; ++i) {
    if (sz[i] > sum - b[i]) isOk = false;
  }
  for (int i = 0; i < n - 1;) {
    int j = i;
    while (j < n - 1 && a[i].first == a[j].first) {
      unite(a[j].second.first, a[j].second.second);
      j++;
    }
    if (!isOk) break;
    if (a[j].first != 0)
      ans = a[j].first;
    else
      ans = a[j - 1].first;
    i = j;
  }
  printf("%d\n", ans);
  return 0;
}
