diff --git a/EquilibriumIndex.py b/EquilibriumIndex.py
index b691b90..54540df 100644
--- a/EquilibriumIndex.py
+++ b/EquilibriumIndex.py
@@ -1,2 +1,11 @@
 def eqindex(data):
-    #do code here
+    indices = []
+    left, right = 0, sum(data)   # initiate left and right sums
+    for index, current in enumerate(data):
+        right -= current    # keep running total of right sum
+        if right == left:
+            indices.append(index)
+        left += current # keep running total of left sum
+    if not indices:
+        return None
+    return indices