#include <stdio.h>
#include <string.h>
#include <stdlib.h>

struct Node {
    int n;
    struct Node *next;
};

struct Node *createNode(int n) {
    struct Node *elem = (struct Node *) malloc(sizeof(struct Node));
    elem->n = n;
    elem->next = NULL;
    return elem;
};

int main() {
    char end = ' ';
    int n;
    struct Node *head1;
    struct Node *head2;
    struct Node *head;
    struct Node *elem;
    struct Node *prev;
    for (int i = 0; i < 10; i++) {
        scanf("%d%c", &n, &end);
        elem = createNode(n);
        if (i == 0) {
            head1 = elem;
            prev = head1;
            continue;
        }
        prev->next = elem;
        prev = elem;
        if (end == '\n')
            break;
    }
    for (int i = 0; i < 10; i++) {
        scanf("%d%c", &n, &end);
        elem = createNode(n);
        if (i == 0) {
            head2 = elem;
            prev = head2;
            continue;
        }
        prev->next = elem;
        prev = elem;
        if (end == '\n')
            break;
    }

    head = createNode(head1->n);
    head1 = head1->next;
    struct Node *headALL = head;
    int i = 0;
    while ((head1 != NULL) || (head2 != NULL)){
        if(head2!=NULL){
            head->next = createNode(head2->n);
            head2 = head2->next;
            head = head->next;
        }
        if(head1!=NULL){
            head->next = createNode(head1->n);
            head1 = head1->next;
            head = head->next;
        }
    }
    while(headALL!=NULL){
        printf("%d ", headALL->n);
        headALL = headALL->next;
    }
}