var  x,  a, s: integer;
begin
x:=99999;

while x<>0 do begin
read(x);
if(x mod 8 = 0) and (x <> 0) then begin
s := s + x;
a:=a+1;
end;

end;
writeln('Ср. ариф: ', s/a:2:1);
end.