Given an array of positive integers nums and a positive integer k.

Return the minimum length of a contiguous subarray of nums such that the sum of all unique elements in that subarray is at least k. If no such subarray exists, return $-1$.

Constraints:

• $1 \leq$ nums.length $\leq 10^5$

• $1 \leq$ nums[i] $\leq 10^5$

• $1 \leq$ k $\leq 10^9$

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