And that polypeptide will not be washed away because it will be physically attached onto that solid surface. Now let's move on to step three. In step three, we basically want to remove the tea bag group before we actually want to add this molecule and form that peptide bond between this amino acid and this amino acid here. So next in step three, we deprotect the nitrogen by removing our Tbock and we mix this molecule with a dilute acid. So for example, we have triflora acetic acid. So CF three, COOH if we mix this with this molecule, we essentially remove our TBA group.