summing values for each item dosn't contain shape(oval) for cells

[Mussa]

hi
I would sum the all values from C: N for each item doesn't contain shape. the result should be in column O with considering will increase data by adding new rows
see the picture

CA.xlsm
	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R
1
2
3
4
5	ITEM	BRAND	MONTH1	MONTH2	MONTH3	MONTH4	MONTH5	MONTH6	MONTH7	MONTH8	MONTH9	MONTH10	MONTH11	MONTH12	TOATAL
6	1	DD-TTR1	0	1	2	3	-1	3	4	-2	0	2	2	2	19
7	2	DD-TTR2	1	-1	2	0	8	9	9	0	1	-4	1	1	27
8	3	DD-TTR3	1	2	3	4	5	4		3	0	1	1	1	24
9	4	DD-TTR4	2	1	2	1	2	3	44	55	66	77	32	1	286
10	5	DD-TTR5	12	3	33	44	55	11	55	88	99	33	11	11	388
11
12
13
14
15
shape

thanks