Competitions

# DSLCS 2011 Number Theory. Favorites

# Divisors

Define the function **f**(**x**) that equals to the number of divisors of **x**. Given two integers **a** and **b** (**a** ≤ **b**), calculate the sum **f**(**a**) + **f**(**a** + **1**) + ... + **f**(**b**).

#### Input

Each line contains two integers **a** and **b** (**1** ≤ **a** ≤ **b** ≤ `2`

- ^{31}**1**). The input is terminated by a line with **a** = **b** = **0**.

#### Output

For each test case print in a separate line the value of **f**(**a**) + **f**(**a** + **1**) + ... + **f**(**b**).

Input example #1

9 12 1 2147483647 0 0

Output example #1

15 46475828386

**Example description:**
9 has 3 divisors: 1, 3, 9; 10 has 4 divisors: 1, 2, 5, 10; 11 has 2 divisors: 1, 11; 12 has 6 divisors: 1, 2, 3, 4, 6, 12; So the answer is 3 + 4 + 2 + 6 = 15.