Help me in solving LB01B problem

help
,
1

My issue

Learning course: C for problem solving - 1
Problem Link: CodeChef: Practical coding for everyone

2

Correct Answer(s):

For A = 3 and C = 4, the output is -1
For A = 3 and C = 5, the output is 4
For A = 2 and C = 4, the output is 3
Explanation:
For A = 3 and C = 4, the output is -1 as the average of 3 and 4 cannot be an integer.

For A = 3 and C = 5, the output is 4 as the average of 3 and 5 is 4 - which is an integer.

For A = 2 and C = 4, the output is 3 as the average of 2 nd 4 is 3 - which is an integer.strong text