#include<bits/stdc++.h>
using namespace std;
int x,y;
int a[100005],b[100005],c[100005]
int main(){
    b[0] = -1;
    scanf("%d",&x);
    for(int i = 1;i <= x;i++){
        scanf("%d",&a[i]);
    }
    scanf("%d",&y);
    for(int i = 1;i <= x;i++){
        scanf("%d",&b[i]);
    }
    printf("%d\n",x);
    sort(a + 1,a + x + 1);
    sort(b + 1,b + y + 1);
    for(int i = 1;i <= x;i++){
        c[i] = a[i];
    }
    for(int i = 1;i <= y;i++){
        if(b[i] != c[i]){
            c[i] = -1;
        }
    }
    for(int i = 1;i <= y;i++){
        if(c[i] != -1){
            printf("%d ",c[i]);
        }
    }
    printf("\n");
    for(int i = 1;i <= x;i++){
        if(a[i] != c[i]){
            printf("%d ",a[i]);
        }
    }
    for(int i = 1;i <= x;i++){
        if(b[i] != c[i]){
            printf("%d ",b[i]);
        }
    }
    return 0;
}