You are given a binary string of length n where all characters are initially $0$, indexed from $1$ to n.

At each step i from $1$ to n, the character at the $1$ based index flips[i - 1] is flipped to $1$.

A binary string is considered prefix aligned at step i if every character from index $1$ to i is $1$ and all other characters from index i + 1 to n are $0$.

Return the total number of steps at which the binary string is prefix aligned.

Constraints:

• n is equal to flips.length

• $1 \leq$ n $\leq 5 imes 10^4$

• flips is a permutation of the integers in the range $[1,$ n$]$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.