pub mod calculater{
    pub mod simple_functions{
        pub fn add (x:i32 , y:i32 ){
            x+y;
        }
         pub fn subtract (x:i32 , y:i32 ){
            x-y;
        }
         pub fn multiply (x:i32 , y:i32 ){
            x*y;
        }
         pub fn divide (x:i32 , y:i32 ){
            x/y;
        }
    }

    pub mod power_functions{
         pub fn square (x:i32){
            x*x;
        }
         pub fn cube (x:i32){
            x*x*x;
        }
        
    }
}