diff --git a/4/4_2.py b/4/4_2.py
new file mode 100755
index 0000000..8d3c407
--- /dev/null
+++ b/4/4_2.py
@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+# 2021 - Advent Of Code - 4 part 2
+
+import re
+
+re_parse = re.compile(r'\s?(\d+)\s+'*4 + r'(\d+)')
+GRID_SIZE = 5
+
+
+class Board:
+
+    def __init__(self, grid):
+        self.grid = grid
+        self.marked = [[0] * GRID_SIZE for _ in range(GRID_SIZE)]
+
+    def print_with_mark(self):
+        for x in range(GRID_SIZE):
+            print(f'{self.grid[x]} \t {self.marked[x]}')
+
+    def mark_number(self, num):
+        for line in range(GRID_SIZE):
+            try:
+                index = self.grid[line].index(num)
+                self.marked[line][index] = 1
+                if self.has_win():
+                    return True
+                return False
+            except ValueError:
+                pass
+        return False
+
+    def has_win(self):
+        # check lines
+        for line in range(GRID_SIZE):
+            if 0 not in self.marked[line]:
+                return True
+
+        # check column
+        for c in range(GRID_SIZE):
+            col_sum = 0
+            for line in range(GRID_SIZE):
+                if self.marked[line][c] == 0:
+                    break
+                else:
+                    col_sum += 1
+            if col_sum == GRID_SIZE:
+                return True
+        return False
+
+    def calc_unmarked(self):
+        unmarked_sum = 0
+        for line in range(GRID_SIZE):
+            for col in range(GRID_SIZE):
+                if self.marked[line][col] == 0:
+                    unmarked_sum += int(self.grid[line][col])
+        return unmarked_sum
+
+
+def parse_file(file):
+    boards_list = []
+    with open(file) as f:
+        numbers = f.readline().split(',')
+
+        line = f.readline()
+        while line:
+            board = []
+            for i in range(GRID_SIZE):
+                line = f.readline()
+                m = re_parse.match(line)
+                grid_line = m.groups()
+                board.append(grid_line)
+
+            b = Board(board)
+            boards_list.append(b)
+            line = f.readline()
+    return boards_list, numbers
+
+
+def play_until_win(boards_list, draws):
+    """ play until win and return last pos """
+
+    for d in draws:
+        for board in boards_list:
+            if board.mark_number(d):
+                print("this board wins !")
+                board.print_with_mark()
+                return board, d
+
+
+def play(boards_list, draws):
+    """ call all numbers
+    could stop when all boards have won ;-) """
+
+    winners = []
+    for d in draws:
+        print(f'calling {d}')
+        winner = ()
+        round_winners = []
+        for board in boards_list:
+            if board.mark_number(d):
+                print("this board wins !")
+                board.print_with_mark()
+                winner = (board, d)
+                round_winners.append(winner)
+
+        if winner:
+            print(f'round winners: {len(round_winners)}')
+            for r in round_winners:
+                boards_list.remove(r[0])
+            winners.extend(round_winners)
+
+    print(f'number of winners: {len(winners)}')
+    return winners
+
+
+boards, draws = parse_file('input.txt')
+print(f'number of boards: {len(boards)}')
+
+# (winning_board, last_num) = play_until_win(boards, draws)
+winning_boards = play(boards, draws)
+
+winning_board, last_num = winning_boards[-1]
+print(f'last number is: {last_num}')
+board_score = winning_board.calc_unmarked()
+print(f'board score: {board_score}')
+
+score = int(last_num) * board_score
+print(f'score is : {score}')