On a merry-go-round that spins counter-clockwise, 9 horses are evenly spaced on the outside perimeter, numbered clockwise. Abe stands next to horse number 1 and starts counting time as the merry-go-round begins to turn. He notices that It takes six seconds for horse number 4 to reach him. How long will it take the merry-go-round to go all the way around once?