Number of Beautiful Partitions

Description

You are given a string s that consists of the digits '1' to '9' and two integers k and minLength.

A partition of s is called beautiful if:

- s is partitioned into k non-intersecting substrings.

- Each substring has a length of at least minLength.

- Each substring starts with a prime digit and ends with a non-prime digit. Prime digits are '2', '3', '5', and '7', and the rest of the digits are non-prime.

Return the number of beautiful partitions of s. Since the answer may be very large, return it modulo 109 + 7.

A substring is a contiguous sequence of characters within a string.