species_1 + species_3 -> species_2 + species_3
species_2 + species_3 -> species_2 + species_4
species_1 + species_4 -> species_2 + species_4
species_2 + species_5 -> species_2 + species_6
species_5 + species_7 -> species_6
species_5 -> species_6
species_6 -> species_6 + species_7
species_6 -> species_6 + species_8
species_2 + species_7 <-> species_9
species_9 -> species_2
species_10 + species_2 <-> species_11
species_4 + species_8 <-> species_12
species_3 + species_8 <-> species_13
0 -> species_3
0 -> species_5
0 -> species_10
0 -> species_1
species_3 -> 0
species_4 -> 0
species_2 -> 0
species_7 -> 0
species_8 -> 0
species_5 -> 0
species_6 -> 0
species_1 -> 0
species_10 -> 0
species_11 -> 0
species_12 -> 0
species_13 -> 0
species_9 -> 0
species_9 -> 0
species_6 -> 0