#include <iostream>
using namespace std;

struct ll {
	int value;
	ll* next;
};

ll* root = NULL;
ll* root1 = NULL;
ll* root2 = NULL;
ll* current = NULL;
ll* tmp;

void insert(ll* lroot, int value){
	if (lroot == NULL){
		lroot = new ll;
		lroot->value = value;
		lroot->next = NULL;
		current = lroot;
		return;
	}
	tmp = new ll;
	tmp->value = value;
	tmp->next = NULL;
	current->next = tmp;
	current = tmp;
	return;
}

void print(ll* lroot){
	current = lroot;
	while (current != NULL) {
        cout << current->value << " -> ";
		current = current->next;
	}
	cout << "NULL\n";
	return;
}

void readll(ll* lroot){
    int value;
    while (1) {
        cin >> value;
        if (!value) break;
        insert(lroot, value);
    }
    print(lroot);
    return;
}
int main() {
    readll(root1);
    readll(root2);
	return 0;
}