AP Grid

Construct an $N \times M$ matrix with entries having **positive** integers such that: - If $M \gt 1$, $i^{th}$ row is **strictly** increasing from left to right with a fixed common difference $d_i$ for all $1\le i \le N$. - If $N \gt 1$, $j^{th}$ column is **strictly** increasing from top to bottom with a fixed common difference $c_j$ for all $1\le j \le M$. - **All** the common differences shoul