#agc046d. [agc046_d]Secret Passage
[agc046_d]Secret Passage
Problem Statement
Given is a string consisting of 0
and 1
. Find the number of strings, modulo , that can result from applying the following operation on zero or more times:
- Remove the two characters at the beginning of , erase one of them, and reinsert the other somewhere in . This operation can be applied only when has two or more characters.
Constraints
- consists of
0
and1
.
Input
Input is given from Standard Input in the following format:
Output
Print the number of strings, modulo , that can result from applying the operation on zero or more times.
Sample Input 1
0001
Sample Output 1
8
Eight strings, 0001
, 001
, 010
, 00
, 01
, 10
, 0
, and 1
, can result.
Sample Input 2
110001
Sample Output 2
24
Sample Input 3
11101111011111000000000110000001111100011111000000001111111110000000111111111
Sample Output 3
697354558