Wolf Down

A certain forest has $N$ animals living in it. Each animal is either a wolf or a bird. Curiously, all the animals live on a straight line, at positions $1, 2, 3, \ldots, N$ on the $x$-axis. You are given a **binary** string $S$ of length $N$, where: - $S_i = 0$ means that the animal living at position $i$ is a bird. - $S_i = 1$ means that the animal living at position $i$ is a wolf. Unfortun