#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define pb(a) push_back(a)
#define pr(a) cout<<(a)<<endl
#define PR(a,b) cout<<(a)<<" "<<(b)<<endl
#define F first
#define S second
#define ll long long
bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,-1,0,1};
typedef pair<int,int> P;

int ord[100001],low[100001];
vector<int> G[100001];
struct edge{int u,v;};
void dfs(int u, int pre, int c, vector<int> G[], vector<edge> &B){
  ord[u] = low[u] = c++;
  for(int i=0;i<G[u].size();i++){
    int v = G[u][i];
    if(v != pre){
      if(ord[v] == -1){
        dfs(v,u,c,G,B);
        low[u] = min(low[u],low[v]);
      } else low[u] = min(low[u],ord[v]);
      if(ord[u] < low[v]) B.push_back((edge){u,v});
    }
  }
}

void bridge(int n, vector<int> G[], vector<edge> &B){
  B.clear();
  int c = 0;
  fill(ord,ord+n,-1);
  for(int i=0;i<n;i++) if(ord[i]==-1) dfs(i,-1,c,G,B);
}

int main() {
  int n,m;
  cin >> n;
  m = n;
  map<P, int> mp;
  int x[100010], y[100010];
  rep(i,m) {
    cin >> x[i] >> y[i];
    x[i]--; y[i]--;
    // mp[{x[i],y[i]}] = i;
    G[x[i]].pb(y[i]);
    G[y[i]].pb(x[i]);
  }

  vector<edge> E;
  bridge(n,G,E);
  vector<P> ans;
  rep(i,E.size()) {
    if(E[i].u>E[i].v) swap(E[i].u,E[i].v);
    ans.pb(P(E[i].u,E[i].v));
  }
  sort(all(ans));
//   rep(i,ans.size()) PR(ans[i].F,ans[i].S);
  rep(i,ans.size()){
      mp[ans[i]]++;
      mp[{ans[i].S, ans[i].F}]++;
  }
  vector<int> ans2;
  rep(i,n){
      if(mp[{x[i], y[i]}] == 0){
          ans2.push_back(i+1);
      }
  }
  cout << ans2.size() << endl;
  for(auto &e: ans2) cout << e << " ";
  cout << endl;

  return 0;
}