diff --git a/main.cpp b/main.cpp
index a08f942..7b696a2 100644
--- a/main.cpp
+++ b/main.cpp
@@ -52,7 +52,7 @@ int main()
         }
         result.push_back(suffix);
 
-        if (input_length > 1 && (middle_digit < 11 || middle_digit > 12))
+        if (input_length > 1 && (last_two_digits < 11 || last_two_digits > 12))
             result.push_back(middle_digit_strings[middle_digit]);
         else
             result.push_back("");