You are given a binary string s (only the characters 0 and 1). Count the number of contiguous substrings that contain an equal number of 0s and 1s and in which all the 0s and all the 1s are grouped together (that is, the substring looks like 0...01...1 or 1...10...0).
Substrings that occur at different positions are counted separately, even if they look the same.
A single line: the binary string s (possibly empty).
A single integer: the number of qualifying substrings.
s <= 100000s contains only the characters 0 and 1.Example 1
Input
00110011
Expected
6
Explanation
The qualifying substrings are "0011", "01", "1100", "10", "0011", and "01" — six in total.
Example 2
Input
10101
Expected
4
Explanation
Every adjacent pair "10" or "01" qualifies: positions give "10", "01", "10", "01" — four in total.
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