Apply Missing number Based on another Cell Value

[hajiali]

in cell B1 I have the following code:

=SMALL(IF(COUNTIF($A$1:$A$153,ROW($1:$153))=0,ROW($1:$153),""),ROW(A1))

and Pressed CTRL + SHIFT + ENTER


Where it finds the missing number in column A1:A153 However, I would like it to Display that value in B1 in C1 only if Sheet2!C(# thats missing) = "<>", otherwise check the next value. EX

SHEET 1

A	B	C
2	1
3	5
4	6
7	8
9	10
12	11

<tbody>
</tbody>

Right now the results would show as above but I want C1 to Check IF(Sheet2!C1= "<>",B1, Go to next value in column B) than to apply the B1 in C1 otherwise go to next value in column B. C2 to check Sheet2!C5 = "any Text" than value 5 in C2. C3 to check Sheet2!C6 =" " than Value 6 is not recorded in C3 to next check value Sheet2!C8 = "Any Text" than value 8 is in C3 . So the check Sheet2!C(# thats in column B)

Sheet 2

A	B	C
		3-15
		4-16
		OFF
		8-15
		OFF
		ON
		ON
		OFF
		ABC
		13

<tbody>
</tbody>

So based on Sheet 2 above Sheet 1 Column C Results should be

SHEET 1

A	B	C
2	1	1
3	5	5
4	6	8
7	8	11
9	10
12	11

<tbody>
</tbody>

I think I need to add a Vlookup or Index to the Above code just dont know how to make it work