Task 3. For real numbers $x$ and $y$, we define $M(x, y)$ as the maximum of the three numbers $x y, (x-1)(y-1)$, and $x+y-2 x y$. Determine the smallest possible value of $M(x, y)$ over all real numbers $x$ and $y$ with $0 \leq x, y \leq 1$.