create undirected edges
adj [ 1 ] . append ( 2 ) NEW_LINE adj [ 2 ] . append ( 1 ) NEW_LINE adj [ 1 ] . append ( 3 ) NEW_LINE adj [ 3 ] . append ( 1 ) NEW_LINE adj [ 2 ] . append ( 4 ) NEW_LINE adj [ 4 ] . append ( 2 ) NEW_LINE adj [ 2 ] . append ( 5 ) NEW_LINE adj [ 5 ] . append ( 2 ) NEW_LINE dp1 = [ 0 ] * ( n + 1 ) NEW_LINE dp2 = [ 0 ] * ( n + 1 ) NEW_LINE