Consider the model of a packet switch

Packets arrive from outside to nodes 1 and 2. Packets depart from nodes 3 and 4. A packetcompleting its service at node 1 goes to node 3 with probability q and goes to node 4 withprobability (1-q). Similarly, a packet completing its service at node 2 goes to node 3 withprobability (1-p) and goes to node 4 with probability p. All interarrival times and service timesare exponentially distributed. There is one buffer at each node in addition to the space in frontof each server. Upon completion of its service at nodes 1 (and 2) a packet attempts to go to node3 or node 4 (with defined probabilities shown in the above picture). If at that time there is apacket receiving service at the destination node and another packet waiting in the buffer, thepacket is lost.

Draw the flowchart of the departure process from node 3.