Give two positive integer c, n. You need to find a pair of integer (a,b) satisfy 1<=a,b<=n and the greatest common division of a and b is c.And you need to maximize the product of a and b
输入描述:
The first line has two positive integer c,n
输出描述:
Output the maximum product of a and b.
If there are no such a and b, just output -1
备注:
1<=c,n<=10^9