program z4_25;
uses crt;
var f:real; x: integer;
BEGIN
clrscr;v writeln('Vvedite zna4enie x=');
readln(x);
if x>0 then f:=x
else
if x=0 then f:=0
else
if x<0 then f:=-(x*x);
writeln('f=',f:3:2);
readln;
END.