Three different 6th grade classes are combining for a square dancing unit.  If possible, the teachers would like each male student to partner with a female student for the unit.  The first class has 17 males and 13 females, while the second class has 14 males and 18 females, and the third class has 15 males and 17 females.  When the classes are combined, how many students will be unable to partner with a student of the opposite gender?
Combining the three classes, there are 17 + 14 + 15 = <<17+14+15=46>>46 male students.
Similarly, there are 13 + 18 + 17 = <<13+18+17=48>>48 female students.
Thus, there are 48-46 = <<48-46=2>>2 students who cannot partner with a student of the opposite gender.
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