已知正方形 $ABCD$ 的边长为 $1$. 当每个 $\lambda_i$（$i=1$，$2$，$3$，$4$，$5$，$6$）都取 $\pm1$ 时，$\left|\lambda_1\overrightarrow{AB}+\allowbreak\lambda_2\overrightarrow{BC}+\allowbreak\lambda_3\overrightarrow{CD}+\allowbreak\lambda_4\overrightarrow{DA}+\allowbreak\lambda_5\overrightarrow{AC}+\allowbreak\lambda_6\overrightarrow{BD}\right|$ 的最小值是______；最大值是______.