Đây nha bạn

Uses Crt;
Var A : Array [1..100] Of Integer;
i , j , n : Integer ;
BEGIN
Clrscr ;
Write(' Do dai cua day so N = ') ; Readln (N) ;
For I := 1 To N Do
Begin
Write ('A[', i , ']= ') ; Readln ( A
) ;
End ;
Writeln (' Cac so khac nhau la : ') ; Writeln ( A[1] ) ;
i := 2 ;
While i <= N Do
Begin
j := 1 ;
While ( j < i ) and ( A[j] <> A ) Do inc(j) ;
If j = i Then Writeln( A ) ;
i :=i + 1 ;
End ; Readln ; END.