diff --git a/ee.c b/ee.c
index e89616b..fd6a8b7 100644
--- a/ee.c
+++ b/ee.c
@@ -54,6 +54,7 @@ arrity(const char query){
      */
     return (query == '+')? 2:
            (query == 'x')? 2:
+           (query == '-')? 2:
            (query == '/')? 2:
            (query == '^')? 2:
            (query == '!')? 1: