#AT1789. C - Secret Number
C - Secret Number
C - Secret Number
Score : $300$ points
Problem Statement
Takahashi has forgotten his PIN. The PIN is a four-digit string consisting of 0, 1, $\ldots$, 9, and may begin with a 0.
For each digit 0 through 9, Takahashi remembers the following fact, represented by a $10$-character string $S_0S_1 \ldots S_9$:
- if $S_i$ is
o: he is certain that the PIN contained the digit $i$; - if $S_i$ is
x: he is certain that the PIN did not contain the digit $i$; - if $S_i$ is
?: he is not sure whether the PIN contained the digit $i$.
How many strings are there that could be Takahashi's PIN?
Constraints
- $S$ is a $10$-character string consisting of
o,x, and?.
Input
Input is given from Standard Input in the following format:
Output
Print the answer.
ooo???xxxx
108
Some of the possible PINs are 0123 and 0021.
o?oo?oxoxo
0
There may be no possible PINs, in which case the answer is $0$.
xxxxx?xxxo
15