import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner sc= new Scanner(system.in);
int n= sc.nextInt();
int []arr= new int[n];
for(int i=0;i<arr.length;i++){
arr[i]=sc.nextInt();
}
for(int j=i+1;j<arr.length;j++){
if(arr[i] != arr[j]){
System.out.println(arr[i]);