diff --git a/requirements.txt b/requirements.txt
index f0aa93a..1a2f7b1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 mypy
+parsimonious
diff --git a/src/JobShopParser/__init__.py b/src/JobShopParser/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/JobShopParser/jobshop1_parser.py b/src/JobShopParser/jobshop1_parser.py
new file mode 100644
index 0000000..a064077
--- /dev/null
+++ b/src/JobShopParser/jobshop1_parser.py
@@ -0,0 +1,19 @@
+from parsomonious.grammar import Grammar
+
+grammar = Grammar(
+        """
+        start           = skip_preface
+        skip_preface    = instance_list / ~"."s skip_preface
+        eol             = \n / \r\n
+        _               = " "
+        instance_list   = problem_instance (sep_line problem_instance eol)* eof
+        problem_instance = strip_whitespace "instance" _ instance_name eol eol sep_line description eol job_data
+        description     = ~".*"
+        instance_name   = ~"\w"
+        sep_line        = strip_whitespace plus_line strip_whitespace eol
+        plus_line       = ~"\+\+\++"
+        eof             = strip_whitespace plus_line " EOF " plus_line strip_whitespace
+        strip_whitespace = ~"[\t ]*"
+        job_data        = ~"[ \r\n0-9]*"s
+        """)
+