#include <iostream> #include <vector> #include <algorithm> using namespace std; int main() { int n, h; cin >> n >> h; vector<int> order; order.push_back(h); for(int i = 0; i < n-1; ++i) { int a, b; cin >> a >> b; auto it = find(order.begin(), order.end(), b); order.insert(it + 1, a); //insert是在迭代器前面插入 所以+1 } int k; cin >> k; for(const int& n: order) { if(n != k) { cout << n << " "; } } return 0; }