[US] Which crate will end up on top of each stack ?

**Description**

**As** Santa Clause
**I want** to know which crate will end up on top of each stack after I reorder them
**So** I can give  the message to the elves

**Input test data**

```[D]    
[N] [C]    
[Z] [M] [P]
1   2   3 

move 1 from 2 to 1
move 3 from 1 to 3
move 2 from 2 to 1
move 1 from 1 to 2
```

Will return CMZ