// editor2
#include<stdio.h>
int main(){
    int n;
    scanf("%d", &n);
    if(n<1){
        printf("Invalid Input");
        return 0;
    }
    int arr[n];
    for(int i=0;i<n;i++){
        scanf("%d", &arr[i]);
    }
    int duplicatesFound=0;
    for(int i=0;i<n;i++){
        int count = 0;
        int alredyPrinted = 0;
        for(int k=0;k<i;k++){
            if(arr[i]==arr[k]){
                alreadyPrinted=1;
                break;
            }
        }
        if(alredyPrinted)continue;
        for(int j=i+1;j<n;j++){
            if(arr[i]==arr[j]){
                count++;
            }
        }
        if(count>0){
            if(duplicatesFound)
            printf(" ");
            printf("%d", arr[i]);
            duplicatedFound=1;
        }
    }
    if(!duplicatesFound){
        printf("No duplicates found");
    }
    return 0;
}