include <stdio.h>

int main() {

int n;
scanf("%d", &n);
int a[n];
for (int i = 0; i < n; i++) {
	scanf("%d", &a[i]);
}
int m;
scanf("%d", &m);
int b[1001];
for (int i = 0; i < 1001; i++) {
	b[i] = 0;
}
for (int i = 0; i < n; i++) {
	b[a[i]]++;
}
int flag = 0;
for (int i = 0; i < 1001; i++) {
	if (b[i] >= m) {
		printf("%d ", i);
		flag = 1;
	}
}
if (flag == 0) {
	printf("-1");
}
return 0;

}