The optimal strategy in the described card game, where red cards earn $1 and green cards result in a $1 loss, ensures a net value of zero, as the initial deck is evenly split. The provided Python program defines a function, `game_value`, that returns this expected value of zero for any even deck size.
The value of this game, assuming you play optimally, is always zero. This is because the deck is initially evenly split between red and green cards, and for each red card won, you lose $1 for each green card. Since the deck is symmetric, on average, you win and lose the same amount, resulting in a net value of zero.
Here's the completion of the Python program:
```python
def game_value(deck_size):
# The value of the game is always zero
return 0.0
# Example usage:
deck_size = 10
result = game_value(deck_size)
print(f"The value of the game with a deck size of {deck_size} is: {result}")
```
This simple program defines the `game_value` function that takes the deck size as input and always returns 0.0, indicating the expected value of the game is zero.