Hacktree

[ducthinh2111]

Testcase 1:

    5

    1 

    2

    2

    1

    2

    5 4 

    2 3

    2 1

    1 4

    2 5       

    2

Expected: 6

Testcase 2:

    5

    2 

    3

    0

    3

    0

    5 4

    2 3         

    3 1

    3 4

    3 5

    3

Expected: 7

Testcase 3:

    4

    1

    1

    1

    1

    4 3

    1 2

    1 4

    4 3

    1

Expected: 8