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