P11000 [Lанqiao Cup 2024 NOI Qualifier Python B] Number of Digit Strings

Xiao Lan wants to construct a digit string of length $10000$ with the following requirements: 1. Xiao Lan does not like the digit $0$, so the digit string must not contain $0$. 2. Xiao Lan likes the digits $3$ and $7$, so the digit string must contain both $3$ and $7$. How many digit strings satisfy the requirements? This number can be very large; you only need to output the result modulo $10^9 + 7$.

N/A

Output one integer in one line, representing the answer.

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