var a,b,c,d:longint;
    e:real;
begin
read(a);
b:=a div 100;
c:=a mod 100;
d:=a+b+c;
e:=d/3;
write(e:0:2);
end.
/**************************************************************
	Problem: 1618
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/