#include <bits/stdc++.h>
using namespace std;
long long n, c, r[200001], u, v, i, t, k;
vector<long long> graph[200001], ans;
bool dfs(long long x, long long p) {
  long long s = 0;
  for (auto i : graph[x])
    if (i != p) s += dfs(i, x);
  if (r[x] && !s) ans.push_back(x);
  return s + (long long)(r[x] && r[p]);
}
int main() {
  cin >> n;
  for (i = 0; i < n - 1; i++) {
    cin >> u >> v >> t, graph[u].push_back(v), graph[v].push_back(u);
    if (t == 2) r[u] = 1, r[v] = 1;
  }
  dfs(1, 0);
  for (cout << ans.size() << endl, i = 0; i < ans.size(); i++)
    cout << ans[i] << ' ';
  return 0;
}
