Online tests surely contain several tests in one file, so:

1. Be sure clean your dictionaries before every test.
2. Be sure read ALL lines of current test, even you got correct answer before all input was used.

This two issues were the reason of my WA1. After fixing them I got "Accepted".

Use the following test to validate mentioned above points:

100
5
5 6 odd
7 8 odd
1 6 even
1 4 odd
7 8 even
3
3
1 1 odd
3 3 odd
1 3 odd
5
4
1 2 even
4 5 even
1 5 odd
3 3 even
10
5
1 2 even
3 4 odd
5 6 even
1 6 even
7 10 odd
20
8
1 9 odd
10 17 odd
18 26 odd
4 5 odd
27 40 even
21 40 odd
1 20 odd
10 20 odd
200
8
1 9 odd
10 17 odd
18 26 odd
4 5 odd
27 40 even
21 40 odd
1 20 odd
10 20 odd
-1
Answer:
4
3
3
3
2
6

Thank you.

Why 6th answer is 2 rather than 6?