func_code_string: #include <bits/stdc++.h>   using namespace std;   void dfs(int node, int par, int gp, int p, vector<int> adj[], vector<int> &src,            vector<int> &dest, vector<int> &ans) {     if (gp % 2 != 0) {       src[node - 1] = !src[node - 1];     }     if (src[node - 1] != dest[node - 1]) {       ans.push_back(node);       int temp = p;       p = gp + 1;       gp = temp;     } else {       int temp = p;       p = gp;       gp = temp;     }     for (int i = 0; i < adj[node].size(); i++) {       if (adj[node][i] != par) {         dfs(adj[node][i], node, gp, p, adj, src, dest, ans);       }     }   }   int main() {     int n;     cin >> n;     vector<int> adj[n + 1];     for (int i = 0; i < n - 1; i++) {       int u, v;       cin >> u >> v;       adj[u].push_back(v);       adj[v].push_back(u);     }     vector<int> src(n);     vector<int> dest(n);     for (int i = 0; i < n; i++) cin >> src[i];     for (int i = 0; i < n; i++) cin >> dest[i];     vector<int> ans;     dfs(1, -1, 0, 0, adj, src, dest, ans);     cout << ans.size() << endl;     for (int i = 0; i < ans.size(); i++) cout << ans[i] << endl;   }   