题目描述
Count the number of distinct sequences a1, a2, ..., an (1 ≤ ai) consisting of positive integers such that gcd(a1, a2, ..., an) = x and $$\sum_{i=1}^{n}a_{i}=y$$. As this number could be large, print the answer modulo 109 + 7.
gcd here means the greatest common divisor.
Input
The only line contains two positive integers x and y (1 ≤ x, y ≤ 109).
Output
Print the number of such sequences modulo 109 + 7.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
3 9
样例输出
3
提示
There are three suitable sequences in the first test: (3, 3, 3), (3, 6), (6, 3).
There are no suitable sequences in the second test.