#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int ms = 1e5 + 20;
const int mx = 5;
const ll mod = 1e9 + 7;

vector<pair<int, int>> adj[ms];
ll dp[ms][mx];

ll dfs(int u, int p, int ci) {
  ll &ans = dp[u][ci];
  if (ans != -1) return ans;
  bool mk[mx] = {0};
  if (u != 0) mk[ci] = 1;

  ans = 1;

  vector<int> vs, cs;

  for (auto e : adj[u]) {
    int v, c;
    tie(v, c) = e;
    if (v == p) continue;
    if (c == -1) {
      vs.push_back(v);
    } else {
      if (mk[c]) {
        return ans = 0;
      }
      mk[c] = 1;
      ans = ans * dfs(v, u, c) % mod;
    }
  }

  for (int i = 0; i < mx; i++) {
    if (!mk[i]) cs.push_back(i);
  }

  if (cs.size() < vs.size()) return ans = 0;
  ll lsc = -1, tt = 0;
  do {
    ll cur = 1, cur_c = 0;
    for (int i = 0; i < vs.size(); i++) {
      cur = cur * dfs(vs[i], u, cs[i]) % mod;
      cur_c *= mx;
      cur_c += cs[i];
    }
    if (cur_c != lsc) {
      tt += cur;
      if (tt >= mod) tt -= mod;
    }
    lsc = cur_c;
  } while(next_permutation(cs.begin(), cs.end()));
  ans = ans * tt % mod;
  return ans;
}

int main() {
  int n;
  cin >> n;
  for (int i = 1; i < n; i++) {
    int u, v, c;
    scanf("%d %d %d", &u, &v, &c);
    u--;
    v--;
    c--;
    adj[u].emplace_back(v, c);
    adj[v].emplace_back(u, c);
  }
  memset(dp, -1, sizeof dp);
  cout << dfs(0, 0, 0) << endl;
}