1r A
https://www.youtube.com/watch?v=-lgipCN55NM
https://www.youtube.com/watch?v=6ODbu5Hqo2I
1rB
https://www.youtube.com/watch?v=wU0QyMiPmhY
https://www.youtube.com/watch?v=U8jN71-v9gI
2n
https://www.youtube.com/watch?v=v3wRoz1O8Vw
3r
https://www.youtube.com/watch?v=wxf9bfgtNls
https://www.youtube.com/watch?v=7nSKiLIrXw0
4t
https://www.youtube.com/watch?v=o1jhpp_3n6w
https://www.youtube.com/watch?v=oiSeDEciFfc