Question 16
Let $m$ and $n$ be two positive integers. Prove that the integer $m^{2} + \left\lceil \frac{4 m^{2}}{n} \right\rceil$ is not a perfect square.
(Here $\lceil x \rceil$ denotes the smallest integer that is not less than $x$.)
(Here $\lceil x \rceil$ denotes the smallest integer that is not less than $x$.)