diff --git a/src/cipher_analytical_machine/cli/cli.clj b/src/cipher_analytical_machine/cli/cli.clj
index ab2ac09..e2dd527 100644
--- a/src/cipher_analytical_machine/cli/cli.clj
+++ b/src/cipher_analytical_machine/cli/cli.clj
@@ -1,5 +1,7 @@
 (ns cipher-analytical-machine.cli.cli
   (:require
+   [cipher-analytical-machine.parsers.parsers :as ps]
+   [cipher-analytical-machine.parsers.gamma :as gamma-ps]
    [cipher-analytical-machine.cli.file :as file]
    [cipher-analytical-machine.symbols.factories :as sf]
    [cipher-analytical-machine.cli.options :as options]
@@ -77,6 +79,15 @@
            (or (contains? options :encrypt)
                (contains? options :decrypt)))
       (cond
+        (and (= (:cipher options) "Caesar")
+             (false? (ps/int-string? (:key options))))
+        {:exit-message (error-msg ["Please, use the key format: [+-](integer)!!! Example: 10, +9, -7."])}
+
+        (and (= (:cipher options) "Gamma")
+             (false? (gamma-ps/key? (:key options))))
+        {:exit-message (error-msg ["Please, use the key format: [+-](integer),[+-](integer),[+-](integer) !!! Example: 10,+9,-7."])}
+
+
         (contains? options :encrypt)
         {:options options :arguments arguments :action-type :encrypt}