Write a C function to find the nth occurrence of an even integer in a sequence of non-negative integers.

Sample Test Cases

	Input	Output
Test Case 1	3 1 2 4 6-1	6
Test Case 2	3 1 -1	-1
Test Case 3	2 1 1 2 3 3 -1	-1
Test Case 4	2 2 2 3 3 -1	2
Test Case 5	1 1 1 2 3 3 -1	2