SAIS concentrations...confused, help!

[tolo]

I 've noticed SAIS has an int'l econ program. My understandings are each student must take the int'l econ program as part of the M.A. study, accompanied with a concentration in the functional or regional studies, such as IDEV, Int'l policy or canadian studies. However, someone said the Int'l econ is the same as IDEV and other concentrations. You only need to choose one of them. Which one is right??? I am really confused...please help! thanks

[IRboundgrad]

All students must complete a concentration in international economics consisting of 6 courses, in addition to their regional or functional concentration's core curriculum.