I have the following recurrence relation and I have no idea how to find it’s time complexity:-

T(n) = T(n-2) + floor((n-2)/2)

I searched through the internet and I got to know about Master Theorem but then I saw that it doesn’t apply to such relationship. I am a beginner and I just can’t understand how to get the time complexity of this recurrence in Big-O. Please help. What is it’s time complexity?