This a good example of "Algorithm First, Coding Second".
The strategy here is "Divide and Conquer" - First find out the positiveness and evenness of the input
SEPARATELY, then make the decision based on the combination of these findings.
Use this pseudo code as a guide:
GET input
SET isEven = 0
SET isPositive = 0
IF (input > 0) THEN
SET isPositive = 1
ELSE IF (input < 0) THEN
SET isPositive = -1
IF (input % 2 == 0) THEN
SET isEven = 1
IF (isPositive == 1 AND isEven == 1) THEN
PRINT 'input is positive and even.'
ELSE IF () THEN
ELSE