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