diff --git a/README.md b/README.md
index 621ddd2f4e31fb563dc0f87490f24c2bd1446c42..67f5df1a917af9bb617f9439d5db87815fb87db6 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,10 @@
 `./main`
 
 
+# Input, Output:
+
+stdin, stdout
+
 # Solves:
 
 2, 3, (6), 7, 8