#include <bits/stdc++.h>

using LL = long long;

const int N = 4e5 + 7;
const int L = 18;
const int MOD = 998244353;

std::vector<std::pair<int, int>> e[N];
std::vector<int> ve[N];
std::pair<int, int> d[N];
int dfn[N], dep[N], sz[N], fa[N][L], cnt;
int a[N], val[N], n, m;
LL ans;

void dfs(int x, int y, int z) {
  sz[x] = 1;
  dfn[x] = ++cnt;
  d[x] = {z, x};
  val[x] = z;
  for(auto &&[v, w]: e[x])
    if(v != y) {
      dep[v] = dep[x] + 1;
      fa[v][0] = x;
      for(int i = 1; i < L; ++i)
	fa[v][i] = fa[fa[v][i - 1]][i - 1];
      dfs(v, x, z ^ w);
      sz[x] += sz[v];
    }
}

int lca(int x, int y) {
  if(dep[x] < dep[y])
    std::swap(x, y);
  for(int i = 0; i < L; ++i)
    if(dep[x] - dep[y] >> i & 1) 
      x = fa[x][i];
  if(x == y)
    return x;
  for(int i = L - 1; i >= 0; --i)
    if(fa[x][i] != fa[y][i]) {
      x = fa[x][i];
      y = fa[y][i];
    }
  return fa[x][0];
}

bool cmp(int x, int y) {
  return dfn[x] < dfn[y];
}

void bvt() {
  a[++m] = 1;
  std::sort(a + 1, a + m + 1, cmp);
  for(int i = 2, _i = m; i <= _i; ++i)
    a[++m] = lca(a[i - 1], a[i]);
  std::sort(a + 1, a + m + 1, cmp);
  m = std::unique(a + 1, a + m + 1) - a - 1;
  for(int i = 1; i <= m; ++i)
    ve[a[i]].clear();
  for(int i = 2; i <= m; ++i) 
    ve[lca(a[i - 1], a[i])].push_back(a[i]);
}

int gdp(int x, int d) {
  for(int i = 0; i < L; ++i)
    if(dep[x] - d >> i & 1)
      x = fa[x][i];
  return x;
}

std::pair<int, int> dp(int x, int y) {
  if(val[x] == y) {
    for(int v: ve[x]) {
      auto [c, s] = dp(v, y);
      ans -= (1LL * c * (n - sz[gdp(v, dep[x] + 1)]) + s);
    }
    return {1, sz[x]};
  }
  int cnt = 0, sz = 0;
  for(int v: ve[x]) {
    auto [c, s] = dp(v, y);
    ans -= (1LL * cnt * s + 1LL * c * sz);
    cnt += c;
    sz += s;
  }
  return {cnt, sz};
}

int main() {

  scanf("%d", &n);
  for(int i = 1, x, y, z; i < n; ++i) {
    scanf("%d%d%d", &x, &y, &z);
    e[x].push_back({y, z});
    e[y].push_back({x, z});
  }

  ans = 1LL * n * (n - 1);
  
  dfs(1, -1, 0);
  std::sort(d + 1, d + n + 1);
  for(int i = 1, j; i <= n; i = j) {
    m = 0;
    for(j = i; j <= n && d[j].first == d[i].first; ++j)
      a[++m] = d[j].second;
    bvt();
    dp(1, d[i].first);
  }

  printf("%lld\n", ans);
  
  return 0;
}