diff --git a/app/main.py b/app/main.py
index 626f41cf..2056720e 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,34 +1,124 @@
 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: int,
+            end: int,
+            is_drowned: bool = False
+    ) -> None:
+        start_x, start_y = start
+        end_x, end_y = end
+        self.is_drowned = is_drowned
+        self.decks = []
 
-    def get_deck(self, row, column):
-        # Find the corresponding deck in the list
-        pass
+        if start_x == end_x:
+            for y_coord in range(
+                    min(start_y, end_y),
+                    max(start_y, end_y) + 1):
+                self.decks.append(Deck(start_x, y_coord))
 
-    def fire(self, row, column):
-        # Change the `is_alive` status of the deck
-        # And update the `is_drowned` value if it's needed
-        pass
+        elif start_y == end_y:
+            for x_coord in range(
+                    min(start_x, end_x),
+                    max(start_x, end_x) + 1):
+                self.decks.append(Deck(x_coord, start_y))
+        else:
+            raise ValueError
+
+    def get_deck(
+            self,
+            row: int,
+            column: int
+    ) -> None:
+        for deck in self.decks:
+            if deck.row == row and deck.column == column:
+                return deck
+        return None
+
+    def fire(
+            self,
+            row: int,
+            column: int
+    ) -> None:
+        deck = self.get_deck(row, column)
+        if deck:
+            deck.is_alive = False
+            for _deck in self.decks:
+                if _deck.is_alive is True:
+                    return
+            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.ships = []
+        self.field = {}
+        for start, end in ships:
+            new_ship = Ship(start, end)
+            self.ships.append(new_ship)
+
+        for ship in self.ships:
+            for deck in ship.decks:
+                coord = (deck.row, deck.column)
+                self.field[coord] = ship
+
+        self._validate_field()
+
+    def print_field(self) -> None:
+        for row in range(10):
+            for colum in range(10):
+                ship = self.field.get((row, colum))
+                if ship:
+                    deck = ship.get_deck(row, colum)
+                    if ship.is_drowned:
+                        print("x", end=" ")
+                    elif not deck.is_alive:
+                        print("*", end=" ")
+                    else:
+                        print("□", end=" ")
+                else:
+                    print("~", end=" ")
+            print()
+
+    def _validate_field(self) -> None:
+        lengths = [len(s.decks) for s in self.ships]
+        if (lengths.count(4) != 1 or lengths.count(3) != 2
+                or lengths.count(2) != 3 or lengths.count(1) != 4):
+            raise ValueError
+        for ship in self.ships:
+            for deck in ship.decks:
+                for dr in range(-1, 2):
+                    for dc in range(-1, 2):
+                        if dr == 0 and dc == 0:
+                            continue
+                        neighbor_coord = (deck.row + dr, deck.column + dc)
+                        neighbor_ship = self.field.get(neighbor_coord)
+
+                        if neighbor_ship and neighbor_ship is not ship:
+                            raise ValueError
+
+    def fire(
+            self,
+            location: tuple
+    ) -> str:
+        if location not in self.field:
+            return "Miss!"
+        target_ship = self.field[location]
+        target_ship.fire(*location)
+        if target_ship.is_drowned:
+            return "Sunk!"
+        return "Hit!"