Grouping city zone by sequentail civic number

hi

i tried to solve by myself but again i have to ask to community.

I have zone and civic number… i have to mark each zone with sequent civic number in the same group, if ther s a zone but a non sequent civic number, the number of the group must be different

I attach the file, the yellow is OUTPUT the green is INPUT. As u can see the result must be in the column 0 the number of the group change when change teh zone OR the zone is not changing but there are not sequantial civic number

I tried with some IF in excel and with join function in string manipulation and use tabel row to variable to loop for each zone, but i can t find a way

Thanks in advice if anyone would help

cheers

STREET_GROUP_u.xlsx