Solution of the Week #319

The answer is 16

w^5 + x^5 + y^5 + z^5 = -8

w^6 + x^6 + y^6 + z^6 = 2

w^7 + x^7 + y^7 + z^7 = 16

 

The values of w,x,y,z in some order are 1, -1, 1+i, 1-i.