Solution -「洛谷 P5176」公约数
DescriptionLink.求$$\sum_{i=1}^n\sum_{j=1}^m\sum_{k=1}^p\gcd(i\cdot j,i\cdot k,j\cdot k)\times \gc...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.