A53=5x4x3=60
One person has two doors, five doors of 1 1 are C5 1, the other four doors of1are C4 1, and the other three doors of C32 are rearranged.
a33c 5 1c 4 1c 32 = 6x 5x 4x 3 = 360
1 1 door, 2 doors, 122, C5 1 door 5, C42 door 4, and then rearrange.
a33c 5 1c 42 = 6x5x 6 = 180
***600