Mars Exploration

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Problem

Sami's spaceship crashed on Mars! She sends sequential SOS messages to Earth for help.

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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.

Input Format

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 .

Constraints

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will contain only uppercase English letters.

Output Format

Print the number of letters in Sami's message that were altered by cosmic radiation.

Time Limit: 5

Memory Limit: 256

Source Limit:

Explanation

Explanation Sample 0

S= SOSSPSSQSSOR, and signal length |S|=12. Sami sent 4 SOS messages (i.e.: 12/4=3).

Expected signal: SOSSOSSOSSOS Recieved signal: SOSSPSSQSSOR We print the number of changed letters, which is 3.

Sample 1

S= SOSSOT, and signal length |S|=6. Sami sent 2 SOS messages (i.e.: 6/3=2).

Expected Signal: SOSSOS Received Signal: SOSSOT We print the number of changed letters, which is 1.