// editor3
#include<stdio.h>
#include<stdbool.h>

int main() {
    int N;
    
    scanf("%d", &N);
    
    if (N < 1) {
        printf("Invalid input\n");
        return 0;
    }
    
    int ids[100];
    
    for (int i = 0; i < N; i++) {
        scanf("%d", &ids[i]);
    }
    
    bool is_duplicate[100] = {false};
    bool found_duplicates = false;
    
    for (int i = 0; i < N; i++) {
        if (!is_duplicate[i]) {
            for (int j = i +1; j < N; j++) {
                if (ids[i] == ids[j]) {
                    if (!found_dupicates) {
                        found_duplicates = true;
                    }
                    printf("%d ", ids[i]);
                    is_duplicate[j] = true;
                }
            }
        }
    }
    
    if (!found_duplicates) {
        printf("No duplicates found\n");
    }
    
    return 0;
     
}