diff --git a/app/main.py b/app/main.py
index 626f41cf..a46f8d9b 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,34 +1,67 @@
 class Deck:
-    def __init__(self, row, column, is_alive=True):
-        pass
+    def __init__(self, row: int, column: int, is_alive: bool = True) -> None:
+        self.row = row
+        self.column = column
+        self.is_alive = is_alive
 
 
 class Ship:
-    def __init__(self, start, end, is_drowned=False):
-        # Create decks and save them to a list `self.decks`
-        pass
+    def __init__(
+            self,
+            start: tuple,
+            end: tuple,
+            is_drowned: bool = False
+    ) -> None:
+        if start[0] != end[0] and start[1] != end[1]:
+            raise ValueError("Ship must be placed horizontally or vertically!")
+        for coord in (start, end):
+            if not (0 <= coord[0] <= 9 and 0 <= coord[1] <= 9):
+                raise ValueError("Ship coordinates must be between 0 and 9!")
+        if start[0] == end[0]:
+            row = start[0]
+            col_start = min(start[1], end[1])
+            col_end = max(start[1], end[1])
+            self.decks = [Deck(row, c) for c in range(col_start, col_end + 1)]
+        else:
+            col = start[1]
+            row_start = min(start[0], end[0])
+            row_end = max(start[0], end[0])
+            self.decks = [Deck(r, col) for r in range(row_start, row_end + 1)]
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+        self.is_drowned = is_drowned
 
-    def fire(self, row, column):
-        # Change the `is_alive` status of the deck
-        # And update the `is_drowned` value if it's needed
-        pass
+    def get_deck(self, row: int, column: int) -> Deck | None:
+        for deck in self.decks:
+            if deck.column == column and deck.row == row:
+                return deck
+        return None
+
+    def fire(self, row: int, column: int) -> None:
+        deck_shot = self.get_deck(row, column)
+        if deck_shot is None:
+            return
+        deck_shot.is_alive = False
+        count = 0
+        for deck in self.decks:
+            if deck.is_alive is False:
+                count += 1
+        if len(self.decks) == count:
+            self.is_drowned = True
 
 
 class Battleship:
-    def __init__(self, ships):
-        # Create a dict `self.field`.
-        # Its keys are tuples - the coordinates of the non-empty cells,
-        # A value for each cell is a reference to the ship
-        # which is located in it
-        pass
-
-    def fire(self, location: tuple):
-        # This function should check whether the location
-        # is a key in the `self.field`
-        # If it is, then it should check if this cell is the last alive
-        # in the ship or not.
-        pass
+    def __init__(self, ships: list) -> None:
+        self.field = {}
+        for ship_tuple in ships:
+            ship_obj = Ship(ship_tuple[0], ship_tuple[1])
+            for deck in ship_obj.decks:
+                self.field[(deck.row, deck.column)] = ship_obj
+
+    def fire(self, location: tuple) -> str:
+        if location not in self.field:
+            return "Miss!"
+        ship = self.field[location]
+        ship.fire(location[0], location[1])
+        if ship.is_drowned:
+            return "Sunk!"
+        return "Hit!"