diff --git a/bit.txt b/bit.txt
index 49daa0c..8e7b53a 100644
--- a/bit.txt
+++ b/bit.txt
@@ -1,3 +1,4 @@
+//Sample input file. Each line should contain a single Bitcoin address only. Add as much addresses as you wish, as long as you have enough RAM for it. FYI, on a PC with 4GB of RAM, it can handle ~5'350'000 addresses. Please remove this line in real use.
 1Q8JppK1R5rx8vtUvqVFqDcoF2A6an7egK
 14sKn1MZZBTvARiJzaSPvoUpacRVrYxitR
 13225yCxivnc1HSib8ek7ZLqcnE4ULBn8k