def checkio(game_result):
    win_posX=[['XXX']
              ['XXX']
              ['XXX']]
    win_posO=[['OOO']
              ['OOO']
              ['OOO']]
    res, pr=[],[]
    for i in win_posX:
        if game_result in win_pos:
            res.append('X')
        else:
            for k in range(len(game_result)):
                    for z in game_result:
                        if z[k][0] == 'X':
                            pr.append('X')
                            if pr == ['X','X','X']: res.append('X')
                        if  z[k][k] == 'X':
                            pr.append('X')
                            if pr == ['X','X','X']: res.append('X')
                        if z[k][2] and z[k][1] and z[k][0]: res.append('X')

    for i in win_posO:
        if game_result in win_pos:
            res.append('O')
        else:
            for k in range(len(game_result)):
                for z in game_result:
                    if z[k][0] == 'O':
                        pr.append('O')
                        if pr == ['O','O','O']: res.append('O')
                    if  z[k][k] == 'O':
                        pr.append('O')
                        if pr == ['O','O','O']: res.append('X')
                    if z[k][2] and z[k][1] and z[k][0]: res.append('O')

    if res == ['X','O']:
        return 'D'
    elif res==['X']:
        return 'X'
    elif res==['O']:
        return 'O'
    else: return -1

if __name__ == '__main__':
    #These "asserts" using only for self-checking and not necessary for auto-testing
    assert checkio([
        "X.O",
        "XX.",
        "XOO"]) == "X", "Xs wins"
    assert checkio([
        "OO.",
        "XOX",
        "XOX"]) == "O", "Os wins"
    assert checkio([
        "OOX",
        "XXO",
        "OXX"]) == "D", "Draw"
    assert checkio([
        "O.X",
        "XX.",
        "XOO"]) == "X", "Xs wins again"