Initialize the tree given in the diagram
addEdge ( adj , 1 , 2 ) ; addEdge ( adj , 1 , 3 ) ; addEdge ( adj , 1 , 4 ) ; addEdge ( adj , 2 , 5 ) ; addEdge ( adj , 2 , 6 ) ; addEdge ( adj , 3 , 7 ) ; addEdge ( adj , 7 , 10 ) ; addEdge ( adj , 7 , 11 ) ; addEdge ( adj , 4 , 8 ) ; addEdge ( adj , 4 , 9 ) ;