program fs;
label 1;
 
var s:string;
    a:integer;
    code:integer;
 
begin
1:
write('Vvedite cislo: ');
readln(s);
 
val(s,a,code);
if code<>0 then begin writeln('Vy vveli nevernoe cislo'); goto 1;  end;
if a<0 then begin writeln('Vy vveli OTRICATELINOE cislo'); goto 1;  end;
 
writeln('SQRT= ',sqrt(a):0:2);
 
readln;
end.