A8756. Little Elephant and Triangle
编程题
普及/提高-
知识点
题目描述
A single line contains two integers $w$ and $h$ $(1<=w,h<=4000)$ .
输入格式
In a single output line print an integer — the remainder of dividing the answer to the problem by $1000000007$ $(10^{9}+7)$ .
输出格式
无
输入输出样例
输入 #1
2 1
输出 #1
36
输入 #2
2 2
输出 #2
240