include

using namespace std;

int main() {

int n;
cin >> n;
int a[n];
int b[1001];
for (int i = 0; i < 1001; i++) {
	b[i] = 0;
}
for (int i = 0; i < n; i++) {
	int t;
	cin >> t;
	b[t]++;
}
int m;
cin >> m;
int f = 0;
for (int i = 0; i < 1001; i++) {
	if (b[i] >= m) {
		cout << i << " ";
		f = 1;
	}
}
if (f == 0) {
	cout << "-1";
}
return 0;

}