Double Summation of Divisor Function

Given two integers n and m, compute the value of

$$\sum_{i=1}^{n}\sum_{j=1}^{m} d(ij)$$

where d(x) denotes the number of divisors of x.

inputFormat

The input consists of two integers n and m separated by a space.

outputFormat

Output a single integer representing the computed summation.

sample

1 1

1