#include<stdio.h>
int main(){
    int N1,N2;
    if(scanf("%d",&N1)!= 1 || N1 <= 0) {
        printf("Invalid input");
        return 0;
    }
    int a[N1];
    for(int i = 0; i < N1;i++){
        scanf("%d",&a[i]);
    }
    if(scanf("%d",&N2)!= 1 || N2 <= 0) {
        printf("Invalid input");
        return 0;
    }
  int b[N2];
  for (int i = 0; i < N2; i++) {
      scanf("%d", &b[i]);
  }
  int merged[N1 + N2];
  int *p = a,*q = b,k = 0;
  for(int i = 0; i < N1; i++) {
      merged[k++] = *(p + i);
  }
  for(int i = 0; i < k; i++) {
      for (int j = i + 1; J < k; j++){
          if(merged[i] > merged[j]) {
              int temp = merged[i];
              merged[i] = merged[j];
              merged[j] = temp;
          }
      }
  }
  for (int i = 0; i < k; i++){
      printf("%d", merged[i]);
  }
  return 0;
}