P9788 [ROIR 2020] Area Planning (Day2)

**Translated from [ROIR 2020](http://neerc.ifmo.ru/school/archive/2019-2020.html) Day2 T2.** ***[Планировка участка](http://neerc.ifmo.ru/school/archive/2019-2020/ru-olymp-regional-2020-day2.pdf)***, translated by Alpha1022. *Translator’s note: Since the original statement was a bit hard for the translator to understand, the meaning is abstracted directly here.* You have four variables $a,b,c,d$ that must satisfy: - $a,b,c,d \in \mathbb N^*$. - $a \ne x, b \ne x$. - $a > c, b > d$. - $a \cdot b - c \cdot d = n$. For given $x,n$, find how many possible assignments of $a,b,c,d$ there are.

The first line contains two integers $n,x$. If $x=0$, it means the second condition is ignored.

One line, the number of valid assignments of $a,b,c,d$.

#### Sample 1 Explanation Only $a=2,b=2,c=1,d=1$ is valid. #### Sample 2 Explanation The following assignments are valid: - $a=2,b=3,c=1,d=1$; - $a=2,b=4,c=1,d=3$; - $a=3,b=2,c=1,d=1$; - $a=3,b=3,c=2,d=2$; - $a=4,b=2,c=3,d=1$. #### Sample 3 Explanation The following assignments are valid: - $a=2,b=4,c=1,d=3$; - $a=4,b=2,c=3,d=1$. #### Constraints For $100\%$ of the testdata, $1 \le n \le 3000, 0 \le x \le 3000$. The detailed limits are shown in the table below: |Subtask ID|Points|Constraints| |:-:|:-:|:-:| |$1$|$11$|$1 \le n \le 50, x=0$| |$2$|$10$|$1 \le n \le 50$| |$3$|$20$|$1 \le n \le 500, x=0$| |$4$|$22$|$1 \le n \le 500$| |$5$|$17$|$1 \le n \le 3000, x=0$| |$6$|$20$|$1 \le n \le 3000$| Translated by ChatGPT 5