using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
using System.Threading;
using System.Runtime.CompilerServices;
static class Program{
	const int mod=(int)1e9+7;
	static List<(int,int)>[] li;
	static bool[] b,h;
	static int[] low,ord;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.Ia;
		int n=s[0],m=n;
		li=new List<(int,int)>[n+1];
		b=new bool[n+1];
		h=new bool[n+1];
		low=new int[n+1];
		ord=new int[n+1];
		for(int i=1;i<=n;i++){li[i]=new List<(int,int)>();}
		for(int i=0;i<m;i++){
			var e=sc.Ia;
			li[e[0]].Add((e[1],i+1));
			li[e[1]].Add((e[0],i+1));
		}

		Fu(1,0,-1);

		var ans=new List<int>();
		for(int i=1;i<=n;i++){
			if(!h[i]){
				ans.Add(i);
			}
		}
		Console.WriteLine(ans.Count);
		Console.WriteLine("{0}",string.Join(" ",ans));
	}
	static void Fu(int a,int g,int p){
		b[a]=true;
		ord[a]=low[a]=g;
		for(int i=0;i<li[a].Count;i++){
			if(!b[li[a][i].Item1]){
				Fu(li[a][i].Item1,g+1,a);
				if(low[li[a][i].Item1]==ord[li[a][i].Item1]){h[li[a][i].Item2]=true;}
			}
			if(li[a][i].Item1!=p){low[a]=Min(low[li[a][i].Item1],low[a]);}
		}
	}
}

public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}