All the positive integers starting with 1 are considered in ascending order of magnitude – and spelled out in conformity with the American system, but disregarding hyphens, spaces, commas and, the word "and" - resulting in this infinite string:

onetwothreefourfivesixseveneightnineteneleventwelve
thirteenfourteenfifteensixteenseventeeneighteennineteen
twentytwentyonetwentytwotwentythreetwentyfour...........

Determine the 2010th letter in the above pattern. What is the 20100th letter in the above pattern?