Insert Edges
addedge ( 0 , 2 ) NEW_LINE addedge ( 1 , 2 ) NEW_LINE addedge ( 2 , 3 ) NEW_LINE addedge ( 3 , 4 ) NEW_LINE addedge ( 4 , 6 ) NEW_LINE addedge ( 4 , 5 ) NEW_LINE addedge ( 5 , 7 ) NEW_LINE addedge ( 5 , 8 ) NEW_LINE print ( numberOfPairs ( N , Y , X ) ) NEW_LINE