import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        Lamp[] lamps = new Lamp[n];
        ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            lamps[i] = new Lamp(i, sc.nextInt());
            graph.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            if (lamps[a].value < lamps[b].value) {
                graph.get(a).add(b);
            } else if (lamps[b].value < lamps[a].value) {
                graph.get(b).add(a);
            }
        }
        Arrays.sort(lamps);
        int k = sc.nextInt();
        boolean[] isOn = new boolean[n];
        for (int i = 0; i < k; i++) {
            isOn[sc.nextInt() - 1] = true;
        }
        StringBuilder sb = new StringBuilder();
        int count = 0;
        for (Lamp x : lamps) {
            if (isOn[x.idx]) {
                count++;
                sb.append(x.idx + 1).append("\n");
                for (int y : graph.get(x.idx)) {
                    isOn[y] ^= true;
                }
            }
        }
        System.out.println(count);
        System.out.print(sb);
    }
    
    static class Lamp implements Comparable<Lamp> {
        int idx;
        int value;
        
        public Lamp(int idx, int value) {
            this.idx = idx;
            this.value = value;
        }
        
        public int compareTo(Lamp another) {
            return value - another.value;
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}