program primer;
begin var x,y:real;
readln(x);
if x<=5
then y:=x**2
else y:=sqrt(25*x);
writeln(y);
end.
program primer;
begin var x,y:real;
readln(x);
if x<=5
then y:=x**2
else y:=sqrt(25*x);
writeln(y);
end.