C++ :

#include<iostream>
#include<cstdlib>
#include<algorithm>
#include<cstring>
using namespace std;
int main()
{
	int n,a[101],g=0;
	bool f[101];
	memset(f,1,sizeof(f));
	cin>>n;
	for(int i=1;i<=n;i++)
		cin>>a[i];
	sort(a+1,a+n+1);
	for(int i=1;i<=n;i++)
		if(a[i]==a[i+1])
		{
			f[i]=0;
			g++;
		}
	cout<<n-g<<endl;
	for(int i=1;i<=n;i++)
		if(f[i]==1)
		    cout<<a[i]<<' ';
	//system("pause");
}

Pascal :

program ex;
var n,x,i,s:integer;
    a:array[1..1000]of integer;

begin
    readln(n);
    for i:=1 to 1000 do
     a[i]:=0;
    for i:=1 to n do
     begin
     read(x);
     a[x]:=1;
     end;
    s:=0;
    for i:=1 to 1000 do
      s:=s+a[i];
    writeln(s);
    for i:=1 to 1000 do
      if a[i]>0 then write(i,' ');
end.