Have a look:
Cover holes 1 and 4, then touch the Mask.
Cover holes 3 and 5, then touch the Mask.
Cover holes 4 and 6, then touch the Mask.
Cover holes 1 and 5, then touch the Mask.
Cover holes 2 and 3, then touch the Mask.
Cover holes 1 and 6, then touch the Mask.