Hi Could someone please help me solve the following situation: I have an array with the following pairs: @pairs = ("1,7","2,6","2,7","5,4","6,7"); I would like to be able to have the following results: "1,7","2,6","2,7","6,7" This result because 1,7 overlap with 2,7 and 6,7 but also because the 6,7 joined the group also the 2,6 must be included. The only pair that does not have nay overlap is "5,4" and should be put in a different group. Thank you very much. Any help would be much appreciated. Thank you very much.