$\color{red}{\text{uses crt;}}$
$\color{GreenYellow}{\text{var n,i:longint;}}$
    $\color{Peach}{\text{a,d: array [1..10000] of longint;}}$
$\color{Bittersweet}{\text{begin}}$
        $\color{CarnationPink}{\text{clrscr;}}$
        $\color{NavyBlue}{\text{write('Nhap n: '); readln(n);}}$
        $\color{RedOrange}{\text{for i:=1 to n do}}$
                $\color{WildStrawberry}{\text{begin}}$
                        $\color{Cerulean}{\text{write('Nhap phan tu thu ',i,':');}}$
                        $\color{Lavender}{\text{read(a[i]);}}$
                        $\color{Turquoise}{\text{inc(d[a[i]]);}}$
                $\color{PineGreen}{\text{end;}}$
        $\color{Aquamarine}{\text{writeln;}}$
        $\color{LimeGreen}{\text{writeln('Nhung phan tu xuat hien 1 lan la: ');}}$
        $\color{Emerald}{\text{for i:=1 to n do}}$
                $\color{YellowOrange}{\text{if d[a[i]]=1 then}}$
                        $\color{Gray}{\text{write(a[i],' ');}}$
        $\color{Mulberry}{\text{readln}}$
$\color{RoyalBlue}{\text{end.}}$