ABC Conjecture 3

You are given a string $S$ of length $N$, containing only the characters `a`, `b`, and `c`. In one move, you can modify $S$ as follows: - Choose three indices $i, j, k$ ($1 \leq i \lt j \lt k \leq |S|$) such that $S_i = \texttt{a}, S_j = \texttt{b}, S_k = \texttt{c}$. That is, choose some [subsequence](https://en.wikipedia.org/wiki/Subsequence) of $S$ that equals `abc`. - Then, delete either th