You are given an integer array rolls of length n and an integer k, representing $n$ rolls of a die with faces numbered from $1$ to k.

Return the length of the shortest sequence of rolls that cannot be formed from rolls.

Note: A sequence of rolls can be formed from rolls if it exists as a subsequence within rolls. A subsequence is derived by deleting zero or more elements from rolls without changing the relative order of the remaining elements.

Constraints:

• n $==$ rolls.length

• $1 \leq$ n $\leq 10^5$

• $1 \leq$ rolls[i] $\leq$ k $\leq 10^5$

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.