Divisors

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

Input

Each line contains two integers $a$ and $b(1\le a\le b\le 2^{31}-1)$. The input is terminated by a line with $a=b=0$.

Output

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

Examples