run the following files in the following sequence:
- python3 router1.py
- python3 nodeA.py
- python3 nodeB.py
- python3 nodeC.py
- python3 nodeD.py
- python3 nodeE.py
- python3 nodeK.py
- python3 nodeL.py
- python3 nodeM.py
- python3 nodeN.py
- python3 nodeO.py
- python3 router2.py
- python3 nodeF.py
- python3 nodeG.py
- python3 nodeH.py
- python3 nodeI.py
- python3 nodeJ.py