CC(C)C[C@@H](CNCC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)c1[nH]cnc1C(=O)N[C@@H](C)CN)NC(=O)c1[nH]cnc1C(=O)N[C@@H](C)C(=O)O.Cl
A higher negative pKa value denotes a less powerful acid. What is this molecule's negative pKa value?