diff --git a/.DS_Store b/.DS_Store
index 055c1b8..6040da5 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/appendix-A/.DS_Store b/appendix-A/.DS_Store
index f8cca9a..cc77c08 100644
Binary files a/appendix-A/.DS_Store and b/appendix-A/.DS_Store differ
diff --git a/ch02/.DS_Store b/ch02/.DS_Store
index 37193d0..39ed28c 100644
Binary files a/ch02/.DS_Store and b/ch02/.DS_Store differ
diff --git a/ch03/.DS_Store b/ch03/.DS_Store
index dec9262..1892cae 100644
Binary files a/ch03/.DS_Store and b/ch03/.DS_Store differ