testcases:
  - name: "testcase 1"
    inputs:
    - 1: 2
    - 2: [[0, 1]]
    output: 
    - 1 : [0, 1]
  - name: "testcase 2"
    inputs:
    - 1: 1
    - 2: []
    output: 
    - 1 : [0]
  - name: "testcase 3"
    inputs:
    - 1: 3
    - 2: [[0, 1], [1, 2]]
    output: 
    - 1 : [1]
  - name: "testcase 4"
    inputs:
    - 1: 4
    - 2: [[1, 0], [1, 2], [2, 3]]
    output: 
    - 1 : [1, 2]
  - name: "testcase 5"
    inputs:
    - 1: 6
    - 2: [[0, 1], [0, 2], [0, 3], [0, 4], [4, 5]]
    output: 
    - 1 : [0, 4]