Question 18
Among all sequences $(x_n)_{n=1}^{2026}$ of $2026$ numbers satisfying $x_1\ge x_2\ge x_3\ge\cdots\ge x_{2026}\ge0$, $x_1+\cdots+x_{2026}\le400$ and $x_1^2+\cdots+x_{2026}^2\ge10000$, determine the minimum value of $\sqrt{x_1}+\sqrt{x_2}$.