解法：

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main() {
	int n, k;
	cin >> n;
	vector<int> arr(n);
	for (auto& x : arr) cin >> x;
	cin >> k;
	int sum = 0;
	for (auto x : arr) {
		if (x == k) sum++;
	}
	if (sum == n) {
		cout << "-1";
	}
	else {
		for (auto x : arr) {
			if (x == k) continue;
			cout << x << " ";
		}
	}
	return 0;
}