def find_winner(seq, seq_dict):
    """
    Identify each round winner.

    :param seq: round sequence
    :type seq: str
    :param seq_dict: players sequences
    :type seq_dict: dict
    :return: winner name as str
    """
    winner_name = ''
    min_index = len(seq)
    for name in seq_dict.keys():
        name_index = seq.find(seq_dict[name])
        if name_index != -1:
            if name_index < min_index:
                winner_name = name
                min_index = name_index
    if len(winner_name) != 0:
        return winner_name
    return None
