What is the external degree of the node indicated in the graph below? \nmermaid\ngraph LR subgraph Left Diamond T1[This Node] L1((•)) R1((•)) B1((•)) T1 --- L1 T1 --- R1 T1 --- B1 L1 --- R1 L1 --- B1 R1 --- B1 end subgraph Right Diamond L2((•)) T2((•)) R2((•)) B2((•)) L2 --- T2 T2 --- R2 R2 --- B2 B2 --- L2 end R1 --- L2