Score : $300$ points
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 $S_0S_1 \ldots S_9$:
o
: he is certain that the PIN contained the digit $i$;x
: he is certain that the PIN did not contain the digit $i$;?
: he is not sure whether the PIN contained the digit $i$.How many strings are there that could be Takahashi's PIN?
o
, x
, and ?
.Input is given from Standard Input in the following format:
$S$
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