def print_all_prefixes(game):
    """
    Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object from python-chess.
    """
    # Start with the root node (the starting position)
    node = game.root()
    
    # Print the empty game (no moves)
    print("Prefix 0:")
    print(node.game())
    print()
    
    # Iterate through the mainline and print each prefix
    prefix_number = 1
    while node.variations:
        node = node.variations[0]  # Follow the first variation (mainline)
        print(f"Prefix {prefix_number}:")
        print(node.game())
        print()
        prefix_number += 1

def print_all_prefixes(game):
    """
    Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object from python-chess.
    """
    # Start with the root node (the starting position)
    node = game.root()
    
    # Print the empty game (no moves)
    print("Prefix 0:")
    print(node.game())
    print()
    
    # Iterate through the mainline and print each prefix
    prefix_number = 1
    while node.variations:
        node = node.variations[0]  # Follow the first variation (mainline)
        print(f"Prefix {prefix_number}:")
        print(node.game())
        print()
        prefix_number += 1

def print_all_prefixes(game):
    """
    Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object from python-chess.
    """
    # Start with the root node (the starting position)
    node = game.root()
    
    # Print the empty game (no moves)
    print("Prefix 0:")
    print(node.game())
    print()
    
    # Iterate through the mainline and print each prefix
    prefix_number = 1
    while node.variations:
        node = node.variations[0]  # Follow the first variation (mainline)
        print(f"Prefix {prefix_number}:")
        print(node.game())
        print()
        prefix_number += 1



import io
import chess.pgn
print_all_prefixes(chess.pgn.read_game(io.StringIO('1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. d4 O-O 5. Bf4 d5 6. Qb3 dxc4 7. Qxc4 c6 8. e4 Nbd7 9. Rd1 Nb6 10. Qc5 Bg4 11. Bg5 Na4 12. Qa3 Nxc3 13. bxc3 Nxe4 14. Bxe7 Qb6 15. Bc4 Nxc3')))

def print_all_prefixes(game):
    """Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object representing a chess game.
    """
    # Create an exporter to convert games to PGN strings
    exporter = chess.pgn.StringExporter(headers=True, variations=True, comments=True)
    
    # Print the initial position (before any moves)
    pgn_string = game.accept(exporter)
    print(pgn_string)
    print()
    
    # Get the main line of moves
    main_line = list(game.mainline_moves())
    
    # For each prefix length
    for i in range(1, len(main_line) + 1):
        # Create a new game with the same headers
        prefix_game = chess.pgn.Game()
        for key, value in game.headers.items():
            prefix_game.headers[key] = value
        
        # Add the moves up to this point
        prefix_game.add_line(main_line[:i])
        
        # Print the PGN string of the prefix game
        pgn_string = prefix_game.accept(exporter)
        print(pgn_string)
        print()

def print_all_prefixes(game):
    """Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object representing a chess game.
    """
    # Create an exporter to convert games to PGN strings
    exporter = chess.pgn.StringExporter(headers=True, variations=True, comments=True)
    
    # Print the initial position (before any moves)
    pgn_string = game.accept(exporter)
    print(pgn_string)
    print()
    
    # Get the main line of moves
    main_line = list(game.mainline_moves())
    
    # For each prefix length
    for i in range(1, len(main_line) + 1):
        # Create a new game with the same headers
        prefix_game = chess.pgn.Game()
        for key, value in game.headers.items():
            prefix_game.headers[key] = value
        
        # Add the moves up to this point
        prefix_game.add_line(main_line[:i])
        
        # Print the PGN string of the prefix game
        pgn_string = prefix_game.accept(exporter)
        print(pgn_string)
        print()

def print_all_prefixes(game):
    """Print the PGN notation for all prefixes of a chess game.
    
    Args:
        game: A chess.pgn.Game object representing a chess game.
    """
    # Create an exporter to convert games to PGN strings
    exporter = chess.pgn.StringExporter(headers=True, variations=True, comments=True)
    
    # Print the initial position (before any moves)
    pgn_string = game.accept(exporter)
    print(pgn_string)
    print()
    
    # Get the main line of moves
    main_line = list(game.mainline_moves())
    
    # For each prefix length
    for i in range(1, len(main_line) + 1):
        # Create a new game with the same headers
        prefix_game = chess.pgn.Game()
        for key, value in game.headers.items():
            prefix_game.headers[key] = value
        
        # Add the moves up to this point
        prefix_game.add_line(main_line[:i])
        
        # Print the PGN string of the prefix game
        pgn_string = prefix_game.accept(exporter)
        print(pgn_string)
        print()



import io
import chess.pgn
print_all_prefixes(chess.pgn.read_game(io.StringIO('1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. d4 O-O 5. Bf4 d5 6. Qb3 dxc4 7. Qxc4 c6 8. e4 Nbd7 9. Rd1 Nb6 10. Qc5 Bg4 11. Bg5 Na4 12. Qa3 Nxc3 13. bxc3 Nxe4 14. Bxe7 Qb6 15. Bc4 Nxc3')))