Squares $$AXYZ$$ and $$A_{1}X_{1}Y_{1}Z_{1}$$ are inscribed in the two congruent right triangle $$ABC$$ and $$PQR$$, as shown below. Find $$AB+AC$$ if $$[AXYZ]=441$$ and $$[A_{1}X_{1}Y_{1}Z_{1}]=440$$.

(第五届AIME1987 第15题)