If you have the tortoise and hare start at 1, but there is a loop going 2 -> 3 -> 2 -> ... then, without moving the tortoise, the hare will never find the torto

If you have the tortoise and hare start at 1, but there is a loop going 2 -> 3 -> 2 -> ... then, without moving the tortoise, the hare will never find the tortoise or the end of the list.