import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int [] now = new int [N+1];
        for(int i=1; i<=N; i++){
            now[i]=i;
        }
        int K = sc.nextInt();
        for(int i=0; i<K; i++){
            int X = sc.nextInt();
            int Y = sc.nextInt();
            int j=1;
            int k=1;
            for(; j<=N; j++){
                if(X==now[j]){
                    break;
                }
            }
            for(;k<=N; k++){
                if(Y==now[k]){
                    break;
                }
            }
            now[j]=Y;
            now[k]=X;
        }
        
        int [] fin = new int [N+1];
        for(int i=1; i<=N; i++){
            fin[i] = sc.nextInt();
        }
        List<String> list = new ArrayList<String>();
        while(true){
            int count=0;
            for(int i=1; i<=N; i++){
                if(now[i]<fin[i]){
                    while(now[i]!=fin[i]){
                        String s = now[i]+" "+(now[i]+1);
                        list.add(s);
                        for(int j=1; j<=N; j++){
                            if(now[i]+1==now[j]){
                                now[i]++;
                                now[j]--;
                                break;
                            }
                        }
                    }
                }else if(now[i]>fin[i]){
                    while(now[i]!=fin[i]){
                        String s = (now[i]-1)+" "+now[i];
                        list.add(s);
                        for(int j=1; j<=N; j++){
                            if(now[i]-1==now[j]){
                                now[i]--;
                                now[j]++;
                                break;
                            }
                        }
                    }
                }else{
                    count++;
                }
            }
            if(count==N){break;}
        }
        
        int l=list.size();
        System.out.println(l);
        for(int i=0; i<l; i++){
            System.out.println(list.get(i));
        }
    }
}