diff --git a/ui.py b/ui.py
new file mode 100644
index 0000000..2c04c9f
--- /dev/null
+++ b/ui.py
@@ -0,0 +1,16 @@
+"""
+Author: Sergey Vartanov (me@enzet.ru).
+"""
+
+import sys
+
+def write_line(number, total):
+    if number == -1:
+        print ('%3s' % '100') + ' %: [' + (100 * '=') + '].'
+    elif number % 1000 == 0:
+        p = number / float(total)
+        l = int(p * 100)
+        print ('%3s' % str(int(p * 1000) / 10)) + ' %: [' + (l * '=') + \
+            ((100 - l) * ' ') + '].'
+        sys.stdout.write("\033[F")
+