#include <stdio.h>

int main() {
    
    int n, i;
    scanf("%d", &n);
    if (n <= 0) {
        printf("Invalid input");
        return 0;
    }
    
    int arr[n];
    for (i = 0; i <= n; i++) {
        scanf("%d", arr[i]);
    }
    int unique[n];
    for (i = 0; i <= n; i++) {
        if (arr[i] != unique[i]) {
            unique[i] = arr[i];
        }
        
    }
    return 0;
}