C = \left[ \begin{matrix} C_{00} += A_{0k}*B_{k0} & C_{01}+= A_{0k}*B_{k1} & \cdots & C_{0N}+= A_{0N}*B_{k0} \\ C_{10} += A_{1k}*B_{k0} & C_{11} += A_{1k}*B_{k1} & \cdots & C_{1N} += A_{1k}*B_{kN} \\ \vdots & \vdots & \ddots & \vdots \\ C_{N0} += A_{0k}*B_{kN} & C_{k1} += A_{Nk}*B_{k1} & \cdots & C_{NN} += A_{Nk}*B_{kN} \\ \end{matrix} \right]