Let \( A=\{n\in \mathbb{N}\mid n^{2}\leq n+10{,}000\}, B=\{3k+1\mid k\in \mathbb{N}\} \) and \( C=\{2k\mid k\in \mathbb{N}\} \), then the sum of all the elements of the set \( A\cap (B-C) \) is equal to ____________.