to add all edges of graph
add_edge ( 0 , 1 , fre ) NEW_LINE add_edge ( 0 , 2 , fre ) NEW_LINE add_edge ( 0 , 3 , fre ) NEW_LINE add_edge ( 0 , 4 , fre ) NEW_LINE add_edge ( 2 , 3 , fre ) NEW_LINE add_edge ( 3 , 4 , fre ) NEW_LINE