区间 [l,rl,rl,r] , 输出 l<=o<=p<=rl <= o <= p <= rl<=o<=p<=r 使 ao⊕ao+1⊕…⊕apa_o \oplus a_{o+1} \oplus…\oplus a_p ao⊕ao+1⊕…⊕ap 值最大
