following is the part of formula which returns wrong result...
SUMPRODUCT(IF(MOD(ROW(1:1),2)=0,-1,1)) result is 1 which is correct
SUMPRODUCT(IF(MOD(ROW(2:2),2)=0,-1,1)) result is -1 which is correct
SUMPRODUCT(IF(MOD(ROW(1:2),2)=0,-1,1)) result is 1, should be zero
why returns wrong...