diff --git a/main.py b/main.py
index 05aba7d88cd4ec8900cd8c77e51db0328e510a23..4c65892d41fe99cf4335ae446d38825f844e30c4 100644
--- a/main.py
+++ b/main.py
@@ -1,5 +1,6 @@
 '''
 W.Wojnowski 2021
+wojciech.wojnowski@pg.edu.pl
 '''
 # imports:
 import tkinter as tk