diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index a992a51a..15b0981a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -134,7 +134,7 @@ repos:
         require_serial: true
         types_or: [jupyter, markdown]
         additional_dependencies:
-          - mypy
+          - mypy==1.13.0
           - pandas-stubs
           - git+https://github.com/numpy/numpy-stubs
           - mypy-extensions
diff --git a/log.ipynb b/log.ipynb
new file mode 100644
index 00000000..1a6467bf
--- /dev/null
+++ b/log.ipynb
@@ -0,0 +1,46 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "0108a30a",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'20.04.2026 Intro is done.'"
+      ]
+     },
+     "execution_count": 1,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "\"\"\"20.04.202677 Intro is done.\"\"\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": ".venv",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.20"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/log.py b/log.py
new file mode 100644
index 00000000..ee6e9242
--- /dev/null
+++ b/log.py
@@ -0,0 +1 @@
+"""20.04.2026 Intro is done."""