题目描述
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.
Examples
Input
1
Output
9
Input
2
Output
98
Input
123
Output
460191684
Input
36018
Output
966522825
Input
1000
Output
184984484
输入格式
见题面
输出格式
见题面
样例输入
1
样例输出
9