How to break a lock<br>Determine whether your padlock has a single-or double-lock shackle. In most cases, this will be impossible to determine by just looking at the padlock. Check its packaging, contact its manufacturers, or research it online to discover what kind of shackle it has.
The padlock says on the back of it what type of shackle it has 
it says you can't tell what kind of shackle by looking at it, I said you can find out what it is by looking at the back of it.
( z1 say :ARG0 ( z2 padlock ) :location ( z3 back :part-of ( z4 it ) ) )