雲泥有別 尘亦生辉

Prime Distance Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 18909   Accepted: 5064 Description The branch of mathematics called number theory is about p

In mathematics, the function d(n) denotes the number of divisors of positive integer n. For example, d(12)=6 because 1,2,3,4,6,12 are all 12's divisors. In this problem, given l,r and k, your task is to calculate the following thing : (∑i=lrd(ik))mod998