Types: n: int, k: int, a: List[int]
Ranges: 2 ≤ n ≤ 8000, n is an even number, 0 ≤ k ≤ min(n/2, 20), 1 ≤ a[i] ≤ n
Addtl Info: a[i] ≠ i, a[i] ≠ a[j] (i ≠ j), a[a[i]] = i