per cases then
( j =0 or j = 1 or j = 2 or j = 3 or j = 4 or j = 5 or j = 6 or j = 7 or j = 8 or j = 9 or j = 10 or j = 11 or j = 12 or j = 13 or j = 14 or j = 15 or j = 16 or j = 17 or j = 18 or j = 19 or j = 20 or j = 21 or j = 22 or j = 23 or j = 24 or j = 25 or j = 26 or j = 27 )
;