digraph G {
  ratio="fill"
  size="4,6"
  edge[style="bold"]

  RT1
  RT2
  RT3
  RT4
  RT5
  RT6
  RT7
  RT8
  RT9
  RT10
  RT11
  RT12

  N1
  N2
  N3
  N4
  N6
  N7
  N8
  N9
  N10
  N11
  N12
  N13
  N14
  N15
  H1

  RT1 -> N1[label="3"]  
  RT1 -> N3[label="1"]  

  RT2 -> N2[label="3"]  
  RT2 -> N3[label="1"]  

  RT3 -> RT6[label="8"]
  RT3 -> N3[label="1"]  
  RT3 -> N4[label="2"]  

  RT4 -> N3[label="1"]  
  RT4 -> RT5[label="8"]

  RT5 -> RT4[label="8"]
  RT5 -> RT6[label="7"]
  RT5 -> RT7[label="6"]
  RT5 -> N12[label="8"]
  RT5 -> N13[label="8"]
  RT5 -> N14[label="8"]

  RT6 -> RT3[label="6"]
  RT6 -> RT5[label="6"]
  RT6 -> RT10[label="7"]

  RT7 -> RT5[label="6"]
  RT7 -> N6[label="1"]  
  RT7 -> N12[label="2"]
  RT7 -> N15[label="9"]

  RT8 -> N6[label="1"]  
  RT8 -> N7[label="4"]  

  RT9 -> N9[label="1"]  
  RT9 -> N11[label="3"]

  RT10 -> RT6[label="5"]
  RT10 -> N6[label="1"]
  RT10 -> N8[label="3"]

  RT11 -> N8[label="2"]
  RT11 -> N9[label="1"]

  RT12 -> N9[label="1"]
  RT12 -> N10[label="2"]
  RT12 -> H1[label="10"]

  N3 -> RT1[label="0"]
  N3 -> RT2[label="0"]
  N3 -> RT3[label="0"]
  N3 -> RT4[label="0"]

  N6 -> RT7[label="0"]
  N6 -> RT8[label="0"]  
  N6 -> RT10[label="0"]  

  N8 -> RT10[label="0"]  
  N8 -> RT11[label="0"]  

  N9 -> RT9[label="0"]
  N9 -> RT11[label="0"]  
  N9 -> RT12[label="0"]  
}