program m1;
var i,p:integer;
begin
read(i);
p:=1;
while i<10 do begin
p:=p*i;
i:=i+2;
end;
writeln(p);
end.
program m1;
var i,p:integer;
begin
read(i);
p:=1;
while i<10 do begin
p:=p*i;
i:=i+2;
end;
writeln(p);
end.