#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

int n;
vector<vector<int>> g;
vector<int> dp1,dp2,dep,ans;

void calcdep(int pre,int now){
    for(auto to:g[now])if(pre!=to){
        dep[to]=(dep[now]+1)%2;
        calcdep(now,to);
    }
}

void dfs1(int pre,int now){
    dp1[now]=dep[now];
    for(auto to:g[now])if(to!=pre) dfs1(now,to);
    for(auto to:g[now])if(to!=pre)if(dp1[to]!=dep[now]) dp1[now]=dp1[to];
}

//depは先行の色
void dfs2(int pre,int now){

    int memo2=dp1[now];

    //答えを求める
    dp2[now]=dep[now];
    for(auto to:g[now])if(dp1[to]!=dep[now]){
        dp2[now]=dp1[to];
        dp1[now]=dp1[to];
    }
    int cnt=0;
    for(auto to:g[now])if(dp1[to]!=dep[now]) cnt++;

    //根を回して再起
    for(auto to:g[now])if(to!=pre){
        //nowをtoの子に回す．後で直すようにmemoしておく
        int memo=dp1[now];

        if(dp1[to]!=dep[now] and cnt==1) dp1[now]=dep[now];
        dfs2(now,to);

        dp1[now]=memo;
    }

    dp1[now]=memo2;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    cin>>n;
    g.resize(n);dp1.resize(n);dp2.resize(n);
    //いるかわからん
    dep.resize(n);dep[0]=0;
    rep(i,n-1){
        int u,v;cin>>u>>v;u--,v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    calcdep(-1,0);
    dfs1(-1,0);
    dfs2(-1,0);
    rep(i,n)if(dep[i]==dp2[i])ans.push_back(i);
    cout<<ans.size()<<endl;
    for(auto x:ans)cout<<x+1<<endl;
    return 0;
}