i

z 1 5 + z 2 5 + z 3 5 + z 4 5 + z 5 5 + z 6 5 = z 5

1

4 5 + 5 5 + 6 5 + 7 5 + 9 5 + 11 5 = 12 5

2

15 5 + 16 5 + 17 5 + 22 5 + 24 5 + 28 5 = 32 5