group_A: 1_core_island_A
group_B: 1_core_island_B
group_C: 1_core_island_C
group_D: 1_core_island_D	2_core_island_D	3_core_island_D
group_E: 1_core_island_E	2_core_island_E	3_core_island_E
group_F: 1_core_island_F	2_core_island_F	3_core_island_F
group_G: 1_core_island_G
group_H: 1_core_island_H