4. (3 points) It is said that Li Bai, the Poetic Immortal of the Tang Dynasty, went to buy wine. He walked on the street, and when he met a shop, his wine doubled; when he saw a flower, he drank 2 cups. On the way, he met shops and flowers four times, and in the end, he had 2 cups of wine left in his flask. The flask originally had $\qquad$ cups of wine.

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4. (3 points) It is said that Li Bai, the Poetic Immortal of the Tang Dynasty, went to buy wine.  
He walked on the street, and when he met a shop, his wine doubled; when he saw a flower, he drank 2 cups.  
On the way, he met shops and flowers four times, and in the end, he had 2 cups of wine left in his flask.  
The flask originally had $\qquad$ cups of wine.
4. (3 points) It is said that during the Tang Dynasty, the poet Li Bai went to drink wine, carrying a pot on the street, doubling the wine when encountering a shop, and drinking 2 cups when seeing flowers. On the way, he met shops and flowers four times, and finally, there were 2 cups of wine left in the pot. The pot originally contained $\qquad$ cups of wine.

【Solution】Solution: Let the pot originally contain $x$ cups of wine. According to the problem:
$$
\begin{array}{l}
\{[(x \times 2-2) \times 2-2] \times 2-2\} \times 2-2=2, \\
\{[(2 x-2) \times 2-2] \times 2-2\} \times 2-2=2, \\
\{[4 x-6] \times 2-2\} \times 2-2=2, \\
\{8 x-14\} \times 2-2=2,
\end{array}
$$
$$
\begin{array}{r}
16 x-30=2, \\
16 x=32, \\
x=2 ;
\end{array}
$$

Answer: The pot originally contained 2 cups of wine.
Therefore, the answer is: 2.