human
Solve in Python:
For a positive integer n, let us define f(n) as the number of digits in base 10.
You are given an integer S.
Count the number of the pairs of positive integers (l, r) (l \leq r) such that f(l) + f(l + 1) + ... + f(r) = S, and find the count modulo 10^9 + 7.

-----Constraints-----
 - 1 \leq S \leq 10^8

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
Print the answer.

-----Sample Input-----
1

-----Sample Output-----
9

There are nine pairs (l, r) that satisfies the condition: (1, 1), (2, 2), ..., (9, 9).
 ... Write me a Python program to find the count modulo 10^9 + 7?
assistant
#Here is Python program to find the count modulo 10^9 + 7.

#!/usr/bin/env python3
import math
import random

class Prime:
    seed_primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]

    def is_prime(self, n):
        is_prime_common = self.is_prime_common(n)
        if is_prime_common is not None:
            return is_prime_common

        if n < 2000000:
            return self.is_prime_bf(n)
        else:
            return self.is_prime_mr(n)

    def is_prime_common(self, n):
        if n == 1: return False
        if n in Prime.seed_primes: return True
        if any([n % x == 0 for x in self.seed_primes]): return False

    def is_prime_bf(self, n):
        for k in range(2, int(math.sqrt(n)) + 1):
            if n % k == 0:
                return False
        return True

    def is_prime_mr(self, n):
        d = n - 1
        while d % 2 == 0:
            d //= 2

        witnesses = self.get_witnesses(n)
        #witnesses = [random.randint(1, n - 1) for _ in range(100)]

        for w in witnesses:
            t = d
            y = pow(w, t, n)

            while t != n - 1 and y != 1 and y != n - 1:
                y = (y ** 2) % n
                t *= 2

            if y != n - 1 and t % 2 == 0:
                return False

        return True

    def get_witnesses(self, num):
        def _get_range(num):
            if num < 2047:
                return 1
            if num < 1373653:
                return 2
            if num < 25326001:
                return 3
            if num < 3215031751:
                return 4
            if num < 2152302898747:
                return 5
            if num < 3474749660383:
                return 6
            if num < 341550071728321:
                return 7
            if num < 38255123056546413051:
                return 9
            return 12

        return self.seed_primes[:_get_range(num)]

    def gcd(self, a, b):
        if a < b:
            a, b = b, a
        if b == 0:
            return a
        while b:
            a, b = b, a % b
       ...