First
Something will be better in the future. If I’m a strong man.
今天是个好天气，哦耶。
$$ sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6} $$
$$ \int_0^1 {x^2} ,{\rm d}x $$
Something will be better in the future. If I’m a strong man.
今天是个好天气，哦耶。
$$ sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6} $$
$$ \int_0^1 {x^2} ,{\rm d}x $$