diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e43b0f9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.DS_Store
diff --git a/bitcoin.pdf b/digital_currency/bitcoin.pdf
similarity index 100%
rename from bitcoin.pdf
rename to digital_currency/bitcoin.pdf
diff --git a/digital_currency/primecoin.pdf b/digital_currency/primecoin.pdf
new file mode 100644
index 0000000..4bd4eaa
Binary files /dev/null and b/digital_currency/primecoin.pdf differ