There is a circle of red and blue tiles. You are given an array of integers colors. The color of tile i is represented by colors[i]:
colors[i] == 0 means that tile i is red.colors[i] == 1 means that tile i is blue.Every 3 contiguous tiles in the circle with alternating colors (the middle tile has a different color from its left and right tiles) is called an alternating group.
Return the number of alternating groups.
Note that since colors represents a circle, the first and the last tiles are considered to be next to each other.
Example 1:
Input: colors = [1,1,1]
Output: 0
Explanation:

Example 2:
Input: colors = [0,1,0,0,1]
Output: 3
Explanation:

Alternating groups:



Constraints:
3 <= colors.length <= 1000 <= colors[i] <= 1