#include <cstdio>
#include <memory>
#define maxn 5001

FILE *in = fopen("secv.in","r"), *out = fopen("secv.out","w");

int n;
int a[maxn];
int b[maxn];


void read()
{
    fscanf(in, "%d", &n);

    for ( int i = 1; i <= n; ++i )
        fscanf(in, "%d", &a[i]);
    char *e = (char*)calloc(2000000000, sizeof(char));

    int k = 0;
    for ( int i = 1; i <= n; ++i )
        if ( e[a[i]] == 0 )
            b[++k] = a[i], e[a[i]] = 1;

}

int main()
{
    read();


	return 0;
}

/*

8
2 1 3 2 1 3 4 5

  1   2   3 4 5

*/