/NUMFINAL - Chữ số tận cùng

<Problem>

http://ntucoder.net/Problem/Details/5528
              Uses Crt;
        Var a,n:longint;
        Begin
            readln(a,n);
            a:=a mod 10;
            case n mod 4 of
                1:writeln(a mod 10);
                2:writeln(a*a mod 10);
                3:writeln(a*a*a mod 10);
                0:writeln(a*a*a*a mod 10);
            end;
            readln;
        End.