uses crt;
var d:real;
    x,t:longint;
begin
clrscr;
read(x);
if x<=50 then t:=1678
 else if x<=100 then t:=1734
  else if x<=200 then t:=2014
   else if x<=300 then t:=2536
    else if x<=400 then t:=2834
     else if x>400 then t:=2927;
d:=((t*x)/10)+t*x;
write(d:0:1);
end.

Program BTT;
Uses crt;
Var tt,kWh: extended;
Begin
        Clrscr;
        Write('Nhap so kWh da dung: '); Readln(kWh);
        If (kWh<0) and (kWh<=50) then tt:=1.678*kWh;
        If (kWh>50) and (kWh<=100) then tt:=1.678*50+1.734*(kWh-50);
        If (kWh>100) and (kWh<=200) then tt:=1.678*50+1.734*50+2.014*(kWh-100);
        If (kWh>200) and (kWh<=300) then tt:=1.678*50+1.734*50+2.014*100+(kWh-200)*2.536;
        If (kWh>300) and (kWh<=400) then tt:=1.678*50+1.734*50+2.014*100+2.536*100+(kWh-300)*2.834;
        If (kWh>400) then tt:=1.678*50+1.734*50+2.014*100+2.536*100+2.834*100+(kWh-400)*2.927;
        tt:=tt+tt*0.1;
        Write('Tong tien phai tra la: ',tt:0:2);
        Readln
End.