Six stations (S1 S6) are connected to an extended LAN through transparent bridges B1 and B2 as shown below. Initially, the forwarding tables are empty. Suppose the following stations transmit frames: S1 transmits to S2, S3 and S6; S3 transmits to S5 and S1; S4 transmits to S3; and S5 transmits to S2. Show the forwarding tables for B1 and B2 with appropriate entries after the frames have been completely transmitted.