#include<stdio.h>

int main(){
    int N, i, j,found = 0;
    scanf("%d",&N);
     if (N< 0){
        printf("Invalid Input");
        return 0;
    }int arr[N];
    for (i = 0; i<N; i++){ 
        scanf("%d",&arr[i]);
        
    for (i= 0;i<N;i++){
    for (j= i+1;j <N; j++){
    if(arr[i] == arr[j]){
        printf("%d",arr[i]);
        found =1;break;
    }
    }
    }
    if (!found){
        printf("No duplicates found");
    }
    return 0;
}