Passwords

Ralph wants to register on three sites. Ralph wants to choose a different password for each site, and all three passwords must be different. Ralph has a favorite string $s$. For the convenience of remembering passwords, Ralph decided to break $s$ into three parts: $a$, $b$ and $c$. We will denote sequential writing of two strings by the operation $+$. Then s = a + b + c. Ralph will use a + b, b + c and a + c as passwords.

Help Ralph to count the number of different ways to split the string $s$ into $a$, $b$ and $c$ so that the resulting passwords are different. Two ways are different if at least one of the strings $a$, $b$ or $c$ is different in them.