group_A → group_D
3 
group_C → group_F
3 
group_E → group_H
3 
group_A → group_C
2 
group_B → group_E
2 
group_C → group_G
1 
group_A
5
group_A
group_B
2
group_B
group_C
4
group_C
group_E
3
group_E
group_D
3
group_D
group_F
3
group_F
group_G
1
group_G
group_H
3
group_H