P9309 [AtCoder] AtCoder Grand Contest 039 - Division by Two with Something
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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