var i,p: integer;
begin
p:=1;
for i:=1 to 20 do
if (i mod 3=0)and(i mod 5=0) then p:=p*i;
writeln(p);
end.
var i,p: integer;
begin
p:=1;
for i:=1 to 20 do
if (i mod 3=0)and(i mod 5=0) then p:=p*i;
writeln(p);
end.