i am still not sure what you trying to achieve here, you need to elaborate your goal and where did you stuck ?
The default port cost is defined by the speed at which the port operates.
10 Gbps Ethernet ports have a port cost of 2,
1 Gbps Ethernet ports have a port cost of 4,
100 Mbps Fast Ethernet ports have a port cost of 19,
and 10 Mbps Ethernet ports have a port cost of 100.
enter the spanning-tree cost value command in interface configuration mode. The value can be between 1 and 200,000,000.
