#include <stdio.h>
int main(){
    int n;
     scanf("%d", &n);
    
    int arr[n];
    int freq [2000001]={0}
    
    for (int i=0; i<n; i++) {
        scanf("%d",&arr[i]);
        freq[arr[i]+1000000]++;
    }
    for (int i=0;i<n;i++){
        if(freq[arr[i]+1000000]== 1) {
            printf("%d\n",arr[i]);
        }
    }
    return 0;
}