#include <bits/stdc++.h>
using namespace std;

int cnt;
vector<int> moves;


void dfs(vector<vector<int>> v, vector<int>& rec, vector<pair<int,int>> pares, int ini, bool changed, bool turn, bool both){
    rec[ini] = 1;
    for(int i = 0; i < v[ini].size(); i++){
        if(rec[v[ini][i]]==0){
            rec[v[ini][i]] = 1;
            if(!both){
                if(!changed){
                    if(pares[v[ini][i]].first != pares[v[ini][i]].second){
                        cnt++;
                        moves.push_back(v[ini][i]);
                        dfs(v,rec,pares,v[ini][i],true,false,false);
                    }
                    else{
                        dfs(v,rec,pares,v[ini][i],false,false,false);
                    }
                }
                else{
                    if(!turn){
                        if(pares[v[ini][i]].first != pares[v[ini][i]].second){
                            cnt++;
                            moves.push_back(v[ini][i]);
                            dfs(v,rec,pares,v[ini][i],true,false,true);
                        }
                        else{
                            dfs(v,rec,pares,v[ini][i],true,true,false);
                        }
                    }
                    else{
                        if(pares[v[ini][i]].first == pares[v[ini][i]].second){
                            cnt++;
                            moves.push_back(v[ini][i]);
                            dfs(v,rec,pares,v[ini][i],false,false,false);
                        }
                        else{
                            dfs(v,rec,pares,v[ini][i],true,false,false);
                        }
                    }
                }
            }
            else{
                if(pares[v[ini][i]].first == pares[v[ini][i]].second){
                      cnt++;
                      moves.push_back(v[ini][i]);
                      dfs(v,rec,pares,v[ini][i],true,true,false);
                }
                else{
                      dfs(v,rec,pares,v[ini][i],true,true,true);
                }
            }
        }
    }
}

int main(){
    int n,x,y;
    cnt = 0;
    cin >> n;
    vector<vector<int>> v(n);
    vector<int> valores(n);
    vector<pair<int,int>> pares(n);
    for(int i = 0; i < n-1; i++){
        cin >> x >> y;
        x--;y--;
        v[y].push_back(x);
    }
    for(int i = 0; i < n; i++){
        cin >> x;
        pares[i].first = x;
    }
    for(int i = 0; i < n; i++){
        cin >> y;
        pares[i].second = y;
    }
    vector<int> rec(n,0);
    if(pares[0].first == pares[0].second){
        dfs(v,rec,pares,0,false,false,false);
    }
    else{
        cnt++;
        moves.push_back(0);
        dfs(v,rec,pares,0,true,false,false);
    }
    cout << cnt << '\n';
    for(auto i : moves){
        cout << i+1 << '\n';
    }
    return 0;
}