Let `M` be a `3xx3` matrix satisfying `M[0 1 0]=M[1-1 0]=[1 1-1],a n dM[1 1 1]=[0 0 12]` Then the sum of the diagonal entries of `M` is _________.

Explanation

To solve the problem, we need to find the sum of the diagonal entries of the matrix \( M \) given the conditions provided. Let's denote the matrix \( M \) as follows:

\[
M = \begin{pmatrix}
a & b & c \\
d & e & f \\
g & h & i
\end{pmatrix}
...