1. Given two vectors $\boldsymbol{a}, \boldsymbol{b}$ satisfy $|\boldsymbol{a}-2 \boldsymbol{b}|=1,|2 \boldsymbol{a}+3 \boldsymbol{b}|=\frac{1}{3}$, then $(5 \boldsymbol{a}-3 \boldsymbol{b}) \cdot(\boldsymbol{a}-9 \boldsymbol{b})$ is . $\qquad$