#include <bits/stdc++.h>
using namespace std;
inline long long getint() {
  long long num = 0, flag = 1;
  char c;
  while ((c = getchar()) < '0' || c > '9')
    if (c == '-') flag = -1;
  while (c >= '0' && c <= '9') num = num * 10 + c - 48, c = getchar();
  return num * flag;
}
struct node {
  int u, v, w;
} e[400005];
int n;
int fir[400005], nxt[400005], to[400005], cnt;
int fa[400005], sz[2][400005];
long long ans;
inline int find(int x) { return x == fa[x] ? x : fa[x] = find(fa[x]); }
int main() {
  n = getint();
  for (int i = 1; i < n; i++)
    e[i].u = getint(), e[i].v = getint(), e[i].w = getint();
  for (int k = 0; k <= 1; k++) {
    for (int i = 1; i <= n; i++) fa[i] = i, sz[k][i] = 1;
    memset(fir, 0, sizeof fir), cnt = 0;
    for (int i = 1; i < n; i++)
      if (e[i].w == k) {
        int r1 = find(e[i].u), r2 = find(e[i].v);
        fa[r2] = r1, sz[k][r1] += sz[k][r2];
      }
    for (int i = 1; i <= n; i++) sz[k][i] = sz[k][find(i)];
  }
  for (int i = 1; i <= n; i++) ans += 1ll * sz[0][i] * sz[1][i];
  printf("%I64d\n", ans - n);
}
