#include <bits/stdc++.h>
using namespace std;
const int maxn = 200005;
struct node {
  int to, val;
};
int n, u, v, w;
vector<node> vec[maxn];
int dp[maxn][2];
template <typename T>
inline void read(T &x) {
  x = 0;
  int f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  x = x * f;
}
long long solve(int cur, int fa, int v) {
  long long res = dp[cur][0] + dp[cur][1], sum0 = 0, sum1 = 0;
  for (int i = 0; i < vec[cur].size(); i++) {
    auto sun = vec[cur][i];
    if (sun.to != fa) {
      if (sun.val)
        sum1 += dp[sun.to][0] + 1;
      else {
        sum0 += dp[sun.to][0] + 1;
        for (int j = 0; j < vec[sun.to].size(); j++) {
          auto son = vec[sun.to][j];
          if (son.to != cur && son.val) sum0 -= dp[son.to][0] + 1;
        }
      }
    }
  }
  for (int i = 0; i < vec[cur].size(); i++) {
    auto sun = vec[cur][i];
    if (sun.to != fa) {
      if (sun.val)
        dp[sun.to][1] = sum0 + sum1 - (dp[sun.to][0] + 1) + dp[cur][1] + 1;
      else {
        if (!v) dp[sun.to][1] += dp[cur][1];
        long long tot = dp[sun.to][0] + 1;
        for (int j = 0; j < vec[sun.to].size(); j++) {
          auto son = vec[sun.to][j];
          if (son.to != cur && son.val) tot -= dp[son.to][0] + 1;
        }
        dp[sun.to][1] += sum0 - tot + 1;
      }
      res += solve(sun.to, cur, sun.val);
    }
  }
  return res;
}
void dfs(int cur, int fa) {
  for (int i = 0; i < vec[cur].size(); i++) {
    if (vec[cur][i].to != fa) {
      dfs(vec[cur][i].to, cur);
    }
  }
  for (int i = 0; i < vec[cur].size(); i++) {
    auto sun = vec[cur][i];
    if (sun.to != fa) {
      if (sun.val)
        dp[cur][0] += dp[sun.to][0] + 1;
      else {
        dp[cur][0] += dp[sun.to][0] + 1;
        for (int j = 0; j < vec[sun.to].size(); j++) {
          auto grand = vec[sun.to][j];
          if (grand.to != cur && grand.val) dp[cur][0] -= dp[grand.to][0] + 1;
        }
      }
    }
  }
}
int main() {
  read(n);
  for (int i = 1; i < n; i++) {
    read(u);
    read(v);
    read(w);
    vec[u].push_back(node{v, w});
    vec[v].push_back(node{u, w});
  }
  dfs(1, 0);
  printf("%lld\n", solve(1, 0, 0));
}
