species_15 + species_2 <-> species_16
species_15 + species_3 <-> species_24
species_2 + species_4 <-> species_5
species_3 + species_4 <-> species_7
species_2 + species_20 <-> species_25
species_20 + species_3 <-> species_19
species_2 + species_9 <-> species_28
species_3 + species_9 <-> species_12
species_16 -> species_2 + species_29
species_24 -> species_23 + species_3
species_5 -> species_14 + species_22
species_7 -> species_14 + species_8
species_25 -> species_26
species_19 -> species_30
species_28 -> species_10 + species_14
species_12 -> species_13 + species_14
species_22 -> species_2 + species_6
species_8 -> species_21 + species_3
species_26 -> species_2 + species_27
species_30 -> species_18 + species_3
species_10 -> species_11
species_13 -> species_17
species_29 -> species_15
species_23 -> species_15
species_27 -> species_20
species_18 -> species_20
species_11 -> species_2 + species_20
species_17 -> species_20 + species_3
species_6 -> 0
species_21 -> 0
species_14 -> 0
species_1 + species_15 <-> species_4
species_1 + species_20 <-> species_9
species_1 + species_16 <-> species_5
species_1 + species_24 <-> species_7
species_1 + species_25 <-> species_28
species_1 + species_19 <-> species_12