题目描述
Given are integers N and X. For each integer k between 0 and X (inclusive), find the answer to the following question, then compute the sum of all those answers, modulo 998244353.
- Let us repeat the following operation on the integer k. Operation: if the integer is currently odd, subtract 1 from it and divide it by 2; otherwise, divide it by 2 and add 2^{N-1} to it. How many operations need to be performed until k returns to its original value? (The answer is considered to be 0 if k never returns to its original value.)
Constraints
- $1 \leq N \leq 2\times 10^5$
- $0 \leq X < 2^N$
- X is given in binary and has exactly N digits. (In case X has less than N digits, it is given with leading zeroes.)
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
N
X
Output
Print the sum of the answers to the questions for the integers between 0 and X (inclusive), modulo 998244353.
Examples
Input
3
111
Output
40
Input
6
110101
Output
616
Input
30
001110011011011101010111011100
Output
549320998
输入格式
见题面
输出格式
见题面
样例输入
30
001110011011011101010111011100
样例输出
549320998