题目描述
Problem Statement
Given an integer N, solve the following problem.
Let f(x)= (The number of positive integers at most x with the same number of digits as x).
Find $f(1)+f(2)+\dots+f(N) modulo 998244353$.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer as an integer.
Constraints
- N is an integer.
- $1 \le N < 10^{18}$
Sample Input 1
16
Sample Output 1
73
- For a positive integer x between 1 and 9, the positive integers at most x with the same number of digits as x are $1,2,\dots,x$.
-
Thus, we have f(1)=1,f(2)=2,...,f(9)=9.
-
For a positive integer x between 10 and 16, the positive integers at most x with the same number of digits as x are $10,11,\dots,x$.
- Thus, we have f(10)=1,f(11)=2,...,f(16)=7.
The final answer is 73.
Sample Input 2
238
Sample Output 2
13870
Sample Input 3
999999999999999999
Sample Output 3
762062362
Be sure to find the sum modulo 998244353.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分