Hidden Cell

There is an $N \times N$ matrix. Let $(i, j)$ denote the cell in the $i$-th row and the $j$-th column, where the rows are numbered $0, 1, \ldots, N - 1$ from top to bottom and the columns are numbered $0, 1, \ldots N-1$ from left to right. There is a hidden cell $(a, b)$. It is known that this cell doesn't lie on the boundary of the matrix. That is, $\min(a, b) \geq 1$ and $\max(a, b) < N - 1$.