#include <stdio.h>
int main() {
    int n, a[100], i, j, found = 0;
    scanf("%d", &n);
    if (n < 1) {
        printf("Invalid input");
        return 0;
    }
    for (i = 0; i < n; i++)
        scanf("%d", &a[i]);
    for (i = 0; i < n; i++)
    for(i = 0; i < n; i++)
        for (j = i + 1; j < n; j++) {
            if (a[i] == a[j]) {
                printf("%d ", a[i]);
                found = 1;
                break;
            }
        }
    }
    if (!found)
        printf("No duplicates found");
    return 0;
}