Insert all data values in the linked list
head = push ( head , 5 ) ; NEW_LINE head = push ( head , 21 ) ; NEW_LINE head = push ( head , 8 ) ; NEW_LINE head = push ( head , 12 ) ; NEW_LINE head = push ( head , 3 ) ; NEW_LINE head = push ( head , 13 ) ; NEW_LINE head = push ( head , 144 ) ; NEW_LINE head = push ( head , 6 ) ; NEW_LINE print ( meanofnodes ( head ) ) NEW_LINE