Dipto and numbers

Dipto is a very smart boy. He loves numbers, especially those in which the sum of the digits is a prime number($example$ 32=3+2=5 which is prime). Given a number $X$ he wants to find the number of terms less than equal to $X$ whose digit sum is a prime number. Unfortunately his semesters are knocking at the door so he needs your help to figure out the number of such terms less than equal to $X$.