Keiko and Tomoko are teaching their friend Suzie to make shumai (dumplings). They need to make 1,000 for a big party. It would take Keiko four hours to make all of them by herself. It would take Tomoko six hours to do the entire job alone. Since Suzie is just learning, it would take her 12 hours to complete the job by herself. How long will it take the three of them working together?

It would take _____ hours for the three girls to complete the job.