5. First write a two-digit number 62, then write the sum of these two digits 8 at the right end of 62, to get 628, then write the sum of the last two digits 2 and 8, which is 10, to get 62810, using the above method to get a 2006-digit integer: $628101123 \cdots$, then the sum of the digits of this integer is ( ).
5. 7018