diff --git a/src/markov.py b/src/markov.py
new file mode 100644
index 0000000..3f32c85
--- /dev/null
+++ b/src/markov.py
@@ -0,0 +1,5 @@
+def main():
+    raise NotImplementedError("Sorry, this project is WIP and didn't implement user functionality yet")
+
+if __name__ == "__main__":
+    main()
diff --git a/src/rulebook.py b/src/rulebook.py
new file mode 100644
index 0000000..90a52d0
--- /dev/null
+++ b/src/rulebook.py
@@ -0,0 +1,16 @@
+"""
+Rulebook class is deisgned to work with strings.
+this class applies markov algorightm to given string
+"""
+
+from dataclasses import dataclass
+from collections import OrderedDict
+
+@dataclass
+class Rulebook:
+    rules: OrderedDict[str, str]
+
+    def __call__(self, string: str):
+        """aplies rule to the given string"""
+        raise NotImplementedError("Sorry, we still don't know how to apply"
+                                  "algorithm to your string")