60. For the sequence of natural numbers $1,2,3,4,5,6, \ldots$, the elimination rule is: any natural number that cannot be expressed as the sum of two composite numbers will be eliminated. For example, “1” should be eliminated; but 12 can be written as the sum of two composite numbers 8 and 4, so it should not be eliminated. The numbers that are retained are arranged in ascending order, and the 2004th number is
Reference answer: 2013