Given two matrices $A$, $B$ with size $n \times m$ and $m \times p$ respectively, where

$
A_{n\times m} = \begin{bmatrix}
a_{11} & a_{12} & \dots & a_{1m} \\
a_{21} & a_{22} & \dots & a_{2m} \\
\vdots & \vdots & \ddots & \vdots \\
a_{n1} & a_{n2} & \dots & a_{nm}
\end{bmatrix}
,\ B_{m\times p} = \begin{bmatrix}
b_{11} & b_{12} & \dots & b_{1p} \\
b_{21} & b_{22} & \dots & b_{2p} \\
\vdots & \vdots & \ddots & \vdots \\
b_{m1} & b_{m2} & \dots & b_{mp}
\end{bmatrix}
$

The result of multiplication of $A$ and $B$ is a matrix with size $n \times p$, where each element

$
ab_{ij} = \displaystyle \sum_{k=1} ^ {m} a_{ik} b_{kj}
,$ for $1 \leq i \leq n$ and $1 \leq j \leq p$