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>[] li;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.Ia;
		int n=s[0],m=s[1];//n-1;
		li=new List<int>[n+1];
		var h=new (int,int)[n];
		var a=sc.Ia2;
		for(int i=1;i<=n;i++){
			h[i-1]=(i,a[i]);
			li[i]=new List<int>();
		}
		for(int i=0;i<m;i++){
			var e=sc.Ia;
			if(a[e[0]]<a[e[1]]){li[e[0]].Add(e[1]);}
			else if(a[e[0]]>a[e[1]]){li[e[1]].Add(e[0]);}
		}
		var q=sc.I;
		var c=sc.Ia;
		var g=new bool[n+1];
		for(int i = 0;i<q;i++) {g[c[i]]=true;}
		Array.Sort(h,(u,v)=>u.Item2-v.Item2);
		int ans=0;
		var lia=new List<int>();
		for(int i = 0;i<n;i++) {
			if(g[h[i].Item1]){
				ans++;
				lia.Add(h[i].Item1);
				for(int j = 0;j<li[h[i].Item1].Count;j++) {g[li[h[i].Item1][j]]^=true;}
			}
		}
		Console.WriteLine("{0}",ans);
		Console.WriteLine("{0}",string.Join("\n",lia));
	}
}

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;}
}