diff --git a/12-pointers/main.go b/12-pointers/main.go
index 72be649..75482c9 100644
--- a/12-pointers/main.go
+++ b/12-pointers/main.go
@@ -27,7 +27,10 @@ func main() {
 	fmt.Printf("%d\n", a)
 
 	b := new(int)
-	*b = 10
+	*b = 12
+	fmt.Printf("b = %p, *b = %d\n", b, *b)
+
+	b = &a
 	fmt.Printf("b = %p, *b = %d\n", b, *b)
 
 	var c *int
diff --git a/13-structs-with-pointer/main.go b/13-structs-with-pointer/main.go
index 075d179..84a3205 100644
--- a/13-structs-with-pointer/main.go
+++ b/13-structs-with-pointer/main.go
@@ -34,9 +34,6 @@ func main() {
 		Age:  27,
 	}
 
-	var _ fmt.Stringer = p
-	var _ fmt.Stringer = &p
-
 	fmt.Println(p)
 
 	p.BeOlder(1)