Please answer my query!!

Main shiv upasak banna chahta hun jiske liye mujhe ek siddh guru ki jarurat hai.....aur siddh guru khojne ke liye mahadev ke naam mantra ka jap karna padega tabhi mahadev mujhe kisi siddh guru se milwaayenge.....toh mahadev ka naam mantra kaun sa hai??? please bata dijiye.