diff --git a/.gitignore b/.gitignore
index 68bc17f..2dc53ca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -157,4 +157,4 @@ cython_debug/
 #  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
-#.idea/
+.idea/
diff --git a/metro/Metro_Line.py b/metro/Metro_Line.py
new file mode 100644
index 0000000..3834cbb
--- /dev/null
+++ b/metro/Metro_Line.py
@@ -0,0 +1,85 @@
+from math import sqrt
+
+
+class Position:
+    def __init__(self, x: int = 0, y: int = 0):
+        self.x = x
+        self.y = y
+
+    def __add__(self, other: "Position") -> "Position":
+        return Position(self.x + other.x, self.y + other.y)
+
+    def __sub__(self, other: "Position") -> "Position":
+        return Position(self.x - other.x, self.y - other.y)
+
+    def __mul__(self, other: float) -> "Position":
+        return Position(int(self.x * other), int(self.y * other))
+
+    def __truediv__(self, other: float) -> "Position":
+        return Position(int(self.x / other), int(self.y / other))
+
+    def __str__(self):
+        return f"({self.x}, {self.y})"
+
+    def distance_to(self, other: "Position") -> float:
+        return sqrt((self.x - other.x) ** 2 + (self.y - other.y) ** 2)
+
+    def norm(self) -> float:
+        return sqrt(self.x ** 2 + self.y ** 2)
+
+class Station:
+    """
+    This class represents the position and link of a metro station.
+    """
+
+    def __init__(self, pos: Position, orientation: float, name: str = "Station"):
+        """
+        Constructor of Station.
+
+        :param pos: Position x and y of the station
+        :param orientation: The orientation of the station in radian (The angle is where the station is facing next)
+        :param name: The name of the station
+        """
+        self.name = name
+        self.orientation = orientation
+        self.pos = pos
+        self.last_station = None
+        self.next_station = None
+
+    def distance_to(self, station: "Station") -> float:
+        """
+        Calculate the distance between two stations.
+
+        :param station: The station to calculate the distance to
+        :return: The distance between two stations
+        """
+        return self.pos.distance_to(station.pos)
+
+
+class Metro_Line:
+    """
+    This class represents the metro line.
+    """
+
+    def __init__(self, name: str = "Metro line A"):
+        """
+        Constructor of Metro_Line.
+
+        :param name: The name of the metro line
+        """
+        self.name = name
+        self.stations = []
+
+    def add_station(self, station: Station):
+        """
+        Add a station to the metro map.
+
+        :param station: The station to be added
+        """
+        self.stations.append(station)
+        if len(self.stations) > 1:
+            self.stations[-2].next_station = station
+            station.last_station = self.stations[-2]
+
+
+__all__ = ["Metro_Line", "Station", "Position"]