diff --git a/README.md b/README.md
index e69de29..0a57713 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,5 @@
+$$
+s_{\Delta B} = \sqrt{\frac{1}{n-1} \sum_{i=1}^{n} (\Delta B_i - \overline{\Delta B})^2}
+$$
+111
+11
\ No newline at end of file