<s>[INST] A $3 \times 3$ matrix $\mathbf{A}$ has entries that are positive integers, so $\mathbf{A} = \begin{pmatrix} a & b & c \\ d & e & f \\ g & h & i \end{pmatrix}$. The sum of each row is $10$, the sum of each column is $10$, and the sum of the six positive integers $a, d, g, c, f, i$ on the red diagonal is $20$. What is the value of $a + b + c + d + e + f + g + h + i$?[/INST]