We end up eliminating 5.86% of total characters, and end up with 45,821 characters and 12,815 unique HLA, resulting in 945,519 total character-HLA pairs.  We end up eliminating 5.86% of total characters, and end up with 45,821 characters and 12,815 unique HLA, resulting in 945,519 total character-HLA pairs. 
 Question: How many different characters were in dataset?
45,821 characters