diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..bf24e2a70ff5d0c2c4d1f5fe9eac4e4436d56cf7
Binary files /dev/null and b/.DS_Store differ
diff --git a/code/.DS_Store b/code/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..2bc8fd2b50a9f83e1788364cd3686590c4e2a9d6
Binary files /dev/null and b/code/.DS_Store differ
diff --git a/code/2021_spring/.DS_Store b/code/2021_spring/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..5a88815ae2920cb4ca26c722ac52475c4b2e4cdf
Binary files /dev/null and b/code/2021_spring/.DS_Store differ