Program HOC24;
var i,a,b: longint;
d: byte;
function t(x: longint): longint;
var j,t1: longint;
begin
t1:=0;
for j:=1 to x do if x mod j=0 then t1:=t1+j;
t:=t1;
end;
begin
write('Nhap a='); readln(a);
write('Nhap b='); readln(b);
d:=0;
for i:=a to b do
if (t(i)/i)=12/5 then d:=d+1;
write(d);
readln
end.