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;
}