Problem Statement
There is a length $L$ string $S$ consisting of uppercase and lowercase English letters displayed on an electronic bulletin board with a width of $W$. The string $S$ scrolls from right to left by a width of one character at a time.
The display repeats a cycle of $L+W-1$ states, with the first character of $S$ appearing from the right edge when the last character of $S$ disappears from the left edge.
For example, when $W=5$ and $S=$ ABC, the board displays the following seven states in a loop:
ABC..BC...C........A...AB..ABC.ABC.
(. represents a position where no character is displayed.)
More precisely, there are distinct states for $k=0,\ldots,L+W-2$ in which the display is as follows.
- Let
$f(x)$be the remainder when$x$is divided by$L+W-1$. The$(i+1)$-th position from the left of the board displays the$(f(i+k)+1)$-th character of$S$when$f(i+k)<L$, and nothing otherwise.
You are given a length $W$ string $P$ consisting of uppercase English letters, lowercase English letters, ., and _.
Find the number of states among the $L+W-1$ states of the board that coincide $P$ except for the positions with _.
More precisely, find the number of states that satisfy the following condition.
- For every
$i=1,\ldots,W$, one of the following holds. - The
$i$-th character of$P$is_.- The character displayed at the
$i$-th position from the left of the board is equal to the$i$-th character of$P$. - Nothing is displayed at the
$i$-th position from the left of the board, and the$i$-th character of$P$is..
- The character displayed at the
Constraints
$1 \leq L \leq W \leq 3\times 10^5$$L$and$W$are integers.$S$is a string of length$L$consisting of uppercase and lowercase English letters.$P$is a string of length$W$consisting of uppercase and lowercase English letters,., and_.
Input
The input is given from Standard Input in the following format:
L W
S
P
Output
Print the answer.
样例
3 5
ABC
..___
3
11 15
abracadabra
__.._________ab
2
20 30
abaababbbabaabababba
__a____b_____a________________
2
1 1
a
_
1
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