Program Hinh_Tron;
uses crt;
var R,cv,s: real;
begin
clrscr;
write('nhap ban kinh R=');
readln(R);
cv:= R*2*3.14;
s:= R*R*3.14;
if R=0 then writeln('R la so am ') else
writeln('chu vi hinh tron la :' ,cv);
writeln('dien tich hinh tron la: ',s);
readln
end.