diff --git a/code/gcd.txt b/code/gcd.txt
index bcdeb55..7e0fbdb 100644
--- a/code/gcd.txt
+++ b/code/gcd.txt
@@ -31,9 +31,23 @@ gto
 :gcd-ret
 $u
 ret
-:main
-4
-16
+:lcm
+=b
+=a
+$a
+$b
 >gcd
 fun
+=gcd
+$a
+$gcd
+div
+$b
+mul
+ret
+:main
+21
+6
+>lcm
+fun
 end