Question 12
The beavers have an ice-cream machine. Chocolate and strawberry ingredients can be supplied at positions 1 and 2. They flow through the pipes from left to right.
The machine has special devices with the following functions:
- Spiral device: changes chocolate to strawberry or strawberry to chocolate.
- Triangle device: chocolate passing through it must move in the arrow's direction. Other ingredients continue without changing direction.
- Pipe-crossing symbol: the pipes at this position do not join.
Today, only one kind of ingredient is available, and it is supplied to both pipes 1 and 2. At which of A and B should flavor-changing devices be placed so that the output is chocolate ice cream regardless of which ingredient is supplied?
The machine has special devices with the following functions:
- Spiral device: changes chocolate to strawberry or strawberry to chocolate.
- Triangle device: chocolate passing through it must move in the arrow's direction. Other ingredients continue without changing direction.
- Pipe-crossing symbol: the pipes at this position do not join.
Today, only one kind of ingredient is available, and it is supplied to both pipes 1 and 2. At which of A and B should flavor-changing devices be placed so that the output is chocolate ice cream regardless of which ingredient is supplied?