Evaluate $i^{11} + i^{16} + i^{21} + i^{28} + i^{31}$.
Powers of i cycle in groups of 4:
i^0 = 1
i^1 = i
i^2 = -1
i^3 = -i
\(i^{11} + i^{16} + i^{21} + i^{28} + i^{31} = -i + 1 + i + 0 - i = \boxed{1-i}\)
+1223 
