diff --git a/src/test/java/org/example/AdministrationTest.java b/src/test/java/org/example/AdministrationTest.java
index 1875272..745926d 100644
--- a/src/test/java/org/example/AdministrationTest.java
+++ b/src/test/java/org/example/AdministrationTest.java
@@ -43,4 +43,21 @@ class AdministrationTest {
 
     }
 
+    @Test
+    void rightPrefix() {
+        Administration administration = new Administration();
+
+        String full01 = "S1002";
+        String full02 = "s100Z";
+        String full03 = "X1004";
+
+
+        boolean test01 = administration.rightPrefix(full01, 1);
+        boolean test02 = administration.rightPrefix(full02, 1);
+        boolean test03 = administration.rightPrefix(full03, 3);
+
+        assertEquals(true, test01);
+        assertEquals(false, test02);
+        assertEquals(false, test03);
+    }
 }
\ No newline at end of file