#include <stdio.h>
void sort(int *start, int length);
void swap(int *a, int *b);

int main() {
    int a[10], b[10], result[20];
    int *aIndex = a, *bIndex = b, *resultIndex = result;
    for (aIndex = a; aIndex < a+10; aIndex++) {
        scanf("%d", aIndex);
    }
    for (bIndex = b; bIndex < b + 10; bIndex++) {
        scanf("%d", bIndex);
    }
    aIndex = a;
    bIndex = b;
    sort(a, 10);
    sort(b, 10);
    aIndex = a;
    bIndex = b;
    while (resultIndex < result + 20) {
        if (*aIndex <= *bIndex || bIndex > b + 9) {
            // aIndex不能越界，要改
            *resultIndex = *aIndex;
            aIndex++;
        }
        else if (*bIndex < *aIndex || aIndex > a + 9) {
            *resultIndex = *bIndex;
            bIndex++;
        }
        resultIndex++;
    }
    resultIndex = result;
    while (resultIndex < result+20) {
        printf("%d ", *resultIndex);
        resultIndex++;
    }
    printf("\n");
    return 0;
}

void sort(int *start, int length) {
    int moved = 1;
    int *index = start;
    while (moved) {
        moved = 0;
        index = start;
        while (index < start + length - 1) {
            if ( *index > *(index + 1)) {
                moved = 1;
                swap(index, index+1);
            }
            index++;
        }
    }
}

void swap(int *a, int *b) {
    int tmp;
    tmp = *a;
    *a = *b;
    *b = tmp;
}