Fibrinopeptides (proteins involved in blood clotting, among other functions) are known to have high amino acid substation rates. Suppose that the average per amino acid site substitution rate in mammalian fibrinogen b (roughly 600 amino acids long) is one substitution every 10 million years. If humans and shrews shared a common ancestor roughly 80 million years ago, ignoring multiple substitutions at the same site, how many amino acid differences should be expect to see between a human and shrew Fibrinogen B sequence?