diff --git a/parse.py b/parse.py
index 2d44875..d3c771b 100644
--- a/parse.py
+++ b/parse.py
@@ -75,7 +75,58 @@ def determine_parts_list(schematic):
     return parts_list
 
 def determine_net_list(schematic):
-    print('NOT IMPLEMENTED')
+    wires = [ record for record in schematic["records"] if record["RECORD"] == "27" ]
+    contacts = [ record for record in schematic["records"] if record["RECORD"] == "2" ]
+    
+    wire_groups = []
+    
+    p = re.compile('^(?P<prefix>X)(?P<index>\d+)$')
+    for wire in wires:
+        coord_name_matches = [x for x in [p.match(key) for key in wire.keys()] if x]
+        wire['coords'] = [ ( int(wire['X' + match.group('index')]) , int(wire['Y' + match.group('index')]) )
+                           for match in coord_name_matches ]
+
+    group_counter = 0
+    for wire_a in wires:
+        other_wires = [wire for wire in wires if wire["index"] != wire_a["index"]]
+        wire_a_vertex_pairs = [(wire_a['coords'][i], wire_a['coords'][i + 1]) for i in
+                               range(len(wire_a['coords']) - 1)]
+        
+        for wire_b in other_wires:
+            wire_b_vertex_pairs = [(wire_b['coords'][i], wire_b['coords'][i + 1]) for i in
+                                   range(len(wire_b['coords']) - 1)]
+            
+            for vertex_a_pair in wire_a_vertex_pairs:
+                for vertex_b_pair in wire_b_vertex_pairs:
+                    if ( (( vertex_a_pair[0][0] <= vertex_b_pair[0][0] <= vertex_a_pair[1][0] )
+                                and ( vertex_a_pair[0][1] <= vertex_b_pair[0][1] <= vertex_a_pair[1][1] ))
+                            or (( vertex_a_pair[0][0] >= vertex_b_pair[0][0] >= vertex_a_pair[1][0] )
+                                and ( vertex_a_pair[0][1] >= vertex_b_pair[0][1] >= vertex_a_pair[1][1] ))
+                            or (( vertex_a_pair[0][0] <= vertex_b_pair[1][0] <= vertex_a_pair[1][0] )
+                                and ( vertex_a_pair[0][1] <= vertex_b_pair[1][1] <= vertex_a_pair[1][1] ))
+                            or (( vertex_a_pair[0][0] >= vertex_b_pair[1][0] >= vertex_a_pair[1][0] )
+                                and ( vertex_a_pair[0][1] >= vertex_b_pair[1][1] >= vertex_a_pair[1][1] )) )\
+                        or ( (( vertex_b_pair[0][0] <= vertex_a_pair[0][0] <= vertex_b_pair[1][0] )
+                                and ( vertex_b_pair[0][1] <= vertex_a_pair[0][1] <= vertex_b_pair[1][1] ))
+                            or (( vertex_b_pair[0][0] >= vertex_a_pair[0][0] >= vertex_b_pair[1][0] )
+                                and ( vertex_b_pair[0][1] >= vertex_a_pair[0][1] >= vertex_b_pair[1][1] ))
+                            or (( vertex_b_pair[0][0] <= vertex_a_pair[1][0] <= vertex_b_pair[1][0] )
+                                and ( vertex_b_pair[0][1] <= vertex_a_pair[1][1] <= vertex_b_pair[1][1] ))
+                            or (( vertex_b_pair[0][0] >= vertex_a_pair[1][0] >= vertex_b_pair[1][0] )
+                                and ( vertex_b_pair[0][1] >= vertex_a_pair[1][1] >= vertex_b_pair[1][1] )) ):
+                        print("line {0} intersects with line {1}".format(vertex_a_pair, vertex_b_pair))
+                        
+                        
+                        
+                        if ( wire_a.get('group', None) != None ) and ( wire_b.get('group', None) == None ):
+                            wire_b['group'] = wire_a['group']
+                        elif (wire_a.get('group', None) == None) and (wire_b.get('group', None) != None):
+                            wire_a['group'] = wire_b['group']
+                        else:
+                            wire_a['group'] = group_counter
+                            wire_b['group'] = group_counter
+                            group_counter += 1
+                        
     return schematic
 
 def main(args):