D2: =MAX(1,MAX(IF(C$1:C2="",ROW(C$1:C2))))

which is an array formula, so commit with Ctrl-Shift-Enter, not justr enter

E2: =IF(AND(C2<0,C3=0),SUM(INDIRECT("C"&D2&":C"&ROW() )),"")

copy D2 and E2 down.

--

HTH

Bob Phillips

(remove nothere from the email address if mailing direct)

"tower_of_love_m" wrote in
message ...
And then start again. Example c1=1,c2=1,c3=1,c4=0 value = 3 (c1-c3) lets
say
c5=1,c6=0 new value =1(c5)