题目描述
Problem Statement
For a positive integer X none of whose digits is 0, consider obtaining a positive integer Y as follows.
- Initialize S as an empty string.
- Let N be the number of digits in X. For $i = 1, \ldots, N$ in this order, do the following: insert the i-th character in the decimal notation of X at the beginning or end of S.
- Let Y be the positive integer represented by the string S.
Let f(X) denote the minimum positive integer that can be obtained from X in this way.
You are given a positive integer Y none of whose digits is 0. Print the number, modulo 998244353, of positive integers X none of whose digits is 0 such that f(X) = Y.
Input
The input is given from Standard Input in the following format:
Y
Output
Print the number, modulo 998244353, of positive integers X none of whose digits is 0 such that f(X) = Y.
Constraints
- Y is a positive integer none of whose digits is 0.
- $1\leq Y < 10^{200000}$
Sample Input 1
1332
Sample Output 1
3
Three integers, 1332, 3132, and 3312, satisfy the conditions.
Sample Input 2
3312
Sample Output 2
0
Sample Input 3
12234433442
Sample Output 3
153
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分