Let\ D be a strong digraph and let \vec{d}(u. \ v) denote the distance between any two vertices in D. A radio mean labeling is a one-to-one mapping f from V(D) to\ N satisfying the condition \vec{d}(u. \ v) +\left\lceil\frac{f\left(u\right)+f(v)}{2}\right\rceil\geq1+\ diam(D) for every u. https://chefesquipmenters.shop/product-category/drip-trays/