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Ishaan is playing with strings these days. He has found a new string. He wants to modify it as per the following rules to make it valid:

  • The string should not have three consecutive same characters (Refer example for explanation).
  • He can add any number of characters anywhere in the string. 

Find the minimum number of characters which Ishaan must insert in the string to make it valid.

Example 1:

S = aabbbcc
Output: 1
Explanation: In aabbbcc 3 b's occur
consecutively, we add a 'd',and Hence,
output will be aabbdbcc.

Example 1:

S = aaaaa
Output: 2
Explanation:  In aaaaa 5 a's occur
consecutively,we need to add 2 'b', and
Hence, the output will be aababaa.

Your Task:
This is a function problem. You only need to complete the function modified() that returns the answer.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(1).

Constraints : 
1 <= Length of S <= 105


** For More Input/Output Examples Use 'Expected Output' option **

Author: goyalanubhav11

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