A charge Q is located inside a rectangular box. The electric flux through each of the six surfaces of the box is: ?1 = +1490 N · m2/C, ?2 = +2400 N · m2/C, ?3 = +4180 N · m2/C, ?4 = -1720 N · m2/C, ?5 = -3750 N · m2/C, and ?6 = -5300 N · m2/C. What is Q?