#include<stdio.h>
#include<stdlib.h>
#include<limits.h>
#define MAX_VAL 1000000
#define MIN_VAL -1000000
#define RANGE (MAX_VAL - MIN_VAL+1)
int counts[RANGE]={0};
int main()
{
    int n;
    if(scanf("%d",&n)!=1)return 1;
    int *arr=(int*)malloc(n*sizeof(int));
    if(arr==NULL)return 1;
    for(int i=0;i<n;i++)
    {
        scanf("%d",&arr[i]);
        courts[arr[i]-MIN_VAL]++;
    }
    for(int i=0;i<n;i++)
    {
        if(courts[arr[i]-MIN_VAL]==1)
        {
            printf("%d\n",arr[i]);
        }
    }
    free(arr);
    return 0;
}