Function reads horizontally

[usuario_estudo]

Hi,

I need a function in SAS that reads horizontally.

I have to create a variable "Number of completed months" that returns the value of months that are filled until it arrives empty (missing ".").

Example: 

ID	MONTH_1	MONTH_2	MONTH_3	MONTH_4	MONTH_5	MONTH_6	MONTH_7	MONTH_8	"Number of completed months"
1	10	22	31	65	.	.	.	.	4
2	152	111	.	.	.	.	.	.	2
3	1	97	198	.	.	.	.	.	3
4	338	67	59	32	12	84	.	.	6
5	100	176	90	220	81	88	887	78	8

Thnak you!

[Astounding]

SAS can do this easily if the data behaves:

n_complete = n(of month_1 - month_8);

However, if you have the possibility of missing values in the middle:

month_1 = 10

month_2 = .

month_3 = 22

You would need to decide if the correct result is 2 vs. should it be 3.  The programming might have to change a little.