fix: formula for mccabe complexity in docstring
diff --git a/mccabe.py b/mccabe.py
index 302ac6d..cc10d7c 100644
--- a/mccabe.py
+++ b/mccabe.py
@@ -84,7 +84,7 @@
 
     def complexity(self):
         """ Return the McCabe complexity for the graph.
-            V-E+2
+            E-V+2
         """
         num_edges = sum([len(n) for n in self.nodes.values()])
         num_nodes = len(self.nodes)