{"raw_statement":[{"iden":"statement","content":"平面上摆放着一个 $n\\times m$ 的点阵，如下图是一个 $3\\times 4$ 的点阵图：\n\n![](https://cdn.luogu.com.cn/upload/image_hosting/6tq3jene.png)\n\n现问，有多少个三元点对组 $(a,b,c)$ 满足 $a,b,c$ 三点共线，顺序无关紧要，例如 $(a,b,c)$ 与 $(b,c,a)$ 算一组。答案对 $10^9+7$ 取模。"},{"iden":"input","content":"一行，两个正整数 $n,m$。"},{"iden":"output","content":"一行一个整数，表示答案对 $10^9+7$ 取模后的结果。"},{"iden":"note","content":"数据保证，$1\\leq n,m\\leq 5\\times 10^4$。"}],"translated_statement":null,"sample_group":[["3 4","20"]],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}