Answer to this guys :
there is a spy who whants to enter into a hiding place for spies so he hides behind a bush and try to figure out the password to enter and he sees the 1 spy :
"six" says a guy behind the door and the spy answers "three" then he enter in the place .
After 2 minutes sees another spy and he hears from behind the door :
"twelve" and the spy says "six" and the spy gets in :
so he tries to enter, thinking that he understood the pass :
"twenty-four" and he answers " twelve" and a guy behind the door kills him