So, this is our tyrosine amino acid. So, tyrosine has an ionizable side chain group, but it is neither basic nor acidic. So the side chain group is this female group. So the PK value of this is 10.9. So in this particular case, because it is ionizable but neither basic nor acidic, what that means is out of these three PKA values, we have to find a middle PKA value. So we have 10.93.1 and eight.