“…However, the lengths of two classes of EAQEC MDS codes derived from our construction are very flexible, and the entanglement bits of three classes of EAQEC MDS codes derived from our construction are very flexible. Constraints Distance References [[ q−1 at , q−1 at − 2d + 6, d; 4]]q q = l 2 , l = atm + 1 is an odd prime power, a be even, or a be odd and t be even [[q + 1, q + 1 − 2d + 6, d; 4]]q q = p 2a , p a ≡ 1 (mod 4) p a + 3 ≤ d ≤ 3p a − 1 and d is even [6] [[q + 1, q + 1 − 2d + 3, d; 1]]q q = p 2a 2 ≤ d ≤ p a and d is even [9] [[q + 1, q − 2d + 11; d, 9]]q q = p 2a , p a ≡ 3 (mod 4), p a > 7 2p a + 4 ≤ d ≤ 4p a − 2 even [28] [[q + 1, q − d + 2, d; d − 1]]q q = p 2a , r | p a − 1 and r ∤ p a + 1 2 ≤ d ≤ (r−1)(p 2a −1) 2 + 2…”