#include <iostream>
using namespace std;
struct ListNode {
int val;
struct ListNode* next;
ListNode(int x) : val(x), next(nullptr) {}
};
int main() {
int n, h, a, b;
cin >> n;
auto* head = new ListNode(0), *ph = new ListNode(0);
cin >> h;
head->val = h;
head->next = nullptr;
n--;
while (n--) {
cin >> a >> b;
for (auto ph = head; ph != nullptr; ph = ph->next) {
if (b == ph->val) {
auto* nd = new ListNode(a);
nd->next = ph->next;
ph->next = nd;
}
}
}
int del;
cin >> del;
for (auto cur = head; cur != nullptr; cur = cur->next) {
if (cur->val != del)cout << cur->val << ' ';
}
}
// 64 位输出请用 printf("%lld")