uses crt;
var
i,N: integer;
S: longint;
begin
write('nhap so N(kw/h)='); readln(N);
For i:=1 to N do
begin
If (n<100) then S:=S+500
If (n>=100) and (N<=200) then S:=S+900
If (N>200) then S:=S+1100
end;
writeln('so tien phai tra la',S,'(dong)');
readln
end.