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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 (ab), calculate the sum f(a) + f(a + 1) + ... + f(b).

Input

Each line contains two integers a and b (1ab231 - 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).

Time limit 1 second
Memory limit 128 MiB
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.