#include<stdio.h>
int main(){
    int a;
    scanf("%d",&a);
   a=int(input())
    if n<0:
    print("Invalid input");
}
else:
    elements=list(map(int,input().split())))
unique_elements=[]
seen=set()
for x in elements:
if x not in seen:
unique_elements.append(x)
seen.add(x)
for x in unique_elements:
print(x,end="")
print()