Update README.md

1 files changed, 8 insertions, 1 deletions

diff --git a/README.md b/README.md
index dca9ccc..e2c5cc5 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,11 @@ These are my solutions for Advent of Code in 2024.  This year I'm using Lua as t
 ./main <<ID>> [<<FILE>>]
 ```
 
-where `<<ID>>` is the day number followed by `a` for the first part or `b` for the second part, e.g. `01b`.  If the file is not specified, it default to the number of the day with two digits and extension `.in`, i.e. `01.in`.  One can use the name of a file that doesn't exist, e.g. `-`, to read from standard input.
+where `<<ID>>` is the day number followed by `a` for the first part or `b` for the second part.  If the file is not specified, it defaults to the number of the day with two digits and extension `.in`, i.e. `01.in`.  One can use the name of a file that doesn't exist, e.g. `-`, to read from standard input.
+
+Example:
+
+```sh
+./main 01b input
+```
+