So we have 20 different possibilities for amino acid number one. And so we have 20 possibilities. The same thing is true for amino acid number two, for amino acid number three, for amino acid number four, number five, number six, number seven, number eight, number nine, and number ten. Now, we have to multiply these out to basically find the total possibility, the total number of possibilities that we can have. And if we multiply these out, we get 20 to the 10th power, and that's about 1.0 24 times ten to 13 possibilities. So 10 trillion possibilities exist for an amino for a protein that consists of only ten amino acids.