题目描述
Background
Reminder during the contest: $0$ is a natural number, and natural numbers are non-negative integers.
Problem Description
Little X encountered a problem:
Given natural numbers $a$ and $b$, find the number of natural number pairs $(x, y)$ that satisfy the following condition:
$$y^2 - x^2 = ax + b$$
He doesn't know how to solve it, so he turns to you, who is proficient in mathematics, for help.
If there are infinitely many natural number pairs that satisfy the condition, you only need to output inf.
Input Format
One line containing two integers $a$ and $b$.
Output Format
If the number of pairs is finite, output one integer on one line, representing the count.
If the number of pairs is infinite, output one string inf on one line.
Sample Input and Output
Sample Input #1
5 15
Sample Output #1
1
Sample Input #2
4 4
Sample Output #2
inf
Sample Input #3
12 6
Sample Output #3
0
Sample Input #4
96 96
Sample Output #4
7
Sample Input #5
10000 9999997
Sample Output #5
6
Notes
Sample #1 Explanation
$$(x, y) = (6, 9)$$
Data Range
This problem uses batched testing.
- Subtask 1 (3 points): $a = b = 0$.
- Subtask 2 (6 points): $0 \le a, b \le 2$, there are no infinite solutions.
- Subtask 3 (9 points): $0 \le a, b \le 100$, there are no infinite solutions.
- Subtask 4 (13 points): $0 \le a, b \le 10^3$, there are no infinite solutions.
- Subtask 5 (14 points): $0 \le a \le 10^4$, $0 \le b \le 10^7$.
- Subtask 6 (14 points): $a = 0$.
- Subtask 7 (14 points): $b = 0$.
- Subtask 8 (27 points): No special restrictions.
For $100\%$ of the data, $0 \le a \le 10^8$, $0 \le b \le 10^{15}$.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分