Код калькулятора на паскаль!

program calc; uses crt; label metka; var a,b,sum: real; symbol1,symbol2,symbol3: char; beginclrscr; writeln; writeln ('vvedite deystvie 4ere3 probel naprimer 4 — 2'); writeln; writeln; metka: readln (a,symbol1,symbol2,symbol3,b); writeln; case symbol2 of'+': sum: =a+b; '-': sum: =a-b; '*': sum: =a*b; '/': sum: =a/b; elsebeginwriteln ('nekorrektno vvedeno deystvie, vvedite pravilno'); goto metka; end; end; writeln ('otvet: ',sum: 6:2,'.'); writeln; writeln ('*'); readln; end.