Sami's spaceship crashed on Mars! She sends sequential SOS messages to Earth for help.
Letters in some of the SOS messages are altered by cosmic radiation during transmission. Given the signal received by Earth as a string, , determine how many letters of Sami's SOS have been changed by radiation.
There is one line of input: a single string, .
Note: As the original message is just SOS repeated times, 's length will be a multiple of .
will contain only uppercase English letters.
Print the number of letters in Sami's message that were altered by cosmic radiation.
Sample Input 0
Sample Output 0
Sample Input 1
Sample Output 1
= SOSSPSSQSSOR, and signal length . Sami sent SOS messages (i.e.: ).