题目描述
Problem Statement
You are given a positive integer X with N digits in decimal representation. None of the digits of X is 0.
For a subset S of $\lbrace 1,2, \ldots, N-1 \rbrace$ , let f(S) be defined as follows.
See the decimal representation of X as a string of length N, and decompose it into |S| + 1 strings by splitting it between the i-th and (i + 1)-th characters if and only if $i \in$ S.
Then, see these |S| + 1 strings as integers in decimal representation, and let f(S) be the product of these |S| + 1 integers.
There are 2^{N-1} subsets of $\lbrace 1,2, \ldots, N-1 \rbrace ,$ including the empty set, which can be S. Find the sum of f(S) over all these S, modulo 998244353.
Input
The input is given from Standard Input in the following format:
N
X
Output
Print the answer.
Constraints
- $2 \leq N \leq 2 \times 10^5$
- X has N digits in decimal representation, none of which is 0.
- All values in the input are integers.
Sample Input 1
3
234
Sample Output 1
418
For $S = \emptyset$, we have f(S) = 234.
For $S = \lbrace 1 \rbrace$, we have $f(S) = 2 \times 34 = 68$.
For $S = \lbrace 2 \rbrace$, we have $f(S) = 23 \times 4 = 92$.
For $S = \lbrace 1, 2 \rbrace$, we have $f(S) = 2 \times 3 \times 4 = 24$.
Thus, you should print 234 + 68 + 92 + 24 = 418.
Sample Input 2
4
5915
Sample Output 2
17800
Sample Input 3
9
998244353
Sample Output 3
258280134
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分