use std::ops::{Add, Div, Mul, Sub};
pub trait Number:
Copy
+ Add<Output = Self>
+ Sub<Output = Self>
+ Mul<Output = Self>
+ Div<Output = Self>
{}
impl<T> Number for T
where
T: Copy
+ Add<Output = T>
+ Sub<Output = T>
+ Mul<Output = T>
+ Div<Output = T>
{}