add branch_0
add branch_4
add branch_5
add branch_9
coalesce branch_0 and branch_9 at time 3.07489698044
coalesce branch_0 and branch_5 at time 7.44087752548
coalesce branch_0 and branch_4 at time 8.27270051952
coalesce branch_7 and branch_0 at time 12.4757528397