diff --git a/chap05/26/main.c b/chap05/26/main.c
index 810c20d..a0a3a0f 100644
--- a/chap05/26/main.c
+++ b/chap05/26/main.c
@@ -1,12 +1,14 @@
 #include <stdio.h>
-void ruler(int a, int b, int h);
-void mark(int h);
+//r represent ruler 
+void r(int a, int b, int h);
+//m represent mark
+void m(int h);
 
 int main(void)
 {
-    ruler(0, 11, 4);
-    mark(30);
-    ruler(4, 20, 4);
+    r(0, 11, 4);
+    m(30);
+    r(4, 20, 4);
     return 0;
 }
 
@@ -19,10 +21,10 @@ void ruler(int a, int b, int h)
     }
 
     mid = a + ((b - a) >> 1);
-    ruler(a, mid, h - 1);
+    r(a, mid, h - 1);
     printf("%2d|", mid);
-    mark(h);
-    ruler(mid + 1, b, h - 1);
+    m(h);
+    r(mid + 1, b, h - 1);
 }
 
 void mark(int h)