The input contains 4 blocks in 4 stacks. From left to right:
- Stack 1 has 1 level.Level 1 has a green block.
- Stack 2 has 1 level.Level 1 has a red block.
- Stack 3 has 1 level.Level 1 has a purple block.
- Stack 4 has 1 level.Level 1 has a blue block.
As such, for the question "What is the color of the block at stack 2, level 1?", the correct answer is "<Output> red".
<Output> red