Dream of building, punched

Dream of snake bite on leg: Would you please tell me the meaning of my dream as it follows... I was going for a walk then suddenly a snake appeared to me and started to chase me, i was running here and there by being affraid i entered one building then also i saw that snake was following me and atlast when i ws climbing on stais then one pin had punched me on my leg and when i turned back and saw my leg then i saw that snake was bitting me and with a great force i shook my leg then that snake falled in the ground and vanished.