diff --git a/leap/leap.py b/leap/leap.py
index 50fd034..45a8d43 100644
--- a/leap/leap.py
+++ b/leap/leap.py
@@ -1,2 +1,12 @@
 def leap_year(year):
-    pass
+    if year % 400 == 0:
+        return True
+    elif year % 100 == 0:
+        return False
+    elif year % 4 == 0:
+        return True
+    else:
+        return False
+
+
+print(leap_year(1999))
\ No newline at end of file