G - Good Sequence

A sequence $B$ of length $M$ is said to be *good* if the number of indices $i$ such that $B_i = i$ is at most $\frac{M}{2}$. Given a sequence $A$ of length $N$, you want to find the length of the longest *good* subsequence of $A$. Please find this value. If no non-empty good subsequence exists, print $0$. ### Input - The first line of input will contain a single integer $T$, denoting the number