def populate_channel_show_dict(channel_show_lst : list):
    """Pass in list of lists [show, channel]. Returns dictionary with channel as key and list of shows as value"""
    
    dictionary = {}
    for item in channel_show_lst:
        if item[1] in dictionary:
            dictionary[item[1]].append(item[0])
        else:
            dictionary[item[1]] = [item[0]]
    return dictionary