Given the below error-free program. a- What does the function mystery1 do? b- What does the function mystery2 do? c- What is the output, and what does it represent? def mysteryl ( x, y ): if x y: return x return y de mystery2( x, y, z ): return mystery1(x, mystery1( y, z) ) print(mystery2 (3, 6, -5))