正整数x 的约数是能整除x 的正整数。正整数x 的约数个数记为div(x)。例如，1，2，

5，10 都是正整数10 的约数，且div(10)=4。设a 和b 是2 个正整数，a≤b，找出a 和b

之间约数个数最多的数x。-Positive integer x can be about a few of the positive integer x divisible. Positive integer x the approximate number recorded as the number of div (x). For example, 1,2,5,10 are about 10 positive integer number, and div (10) = 4. Set a and b are two positive integers, a ≤ b, to find a and b between about a few number of the largest number of x.