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. Some positive integer x the number recorded as the number of div (x). For example, 1,2,5,10 are about 10 positive integer number, and div (10) = 4. For a and b are two positive integers, a < = b, find a and b between the number of up to about a few of the number of x.