def get_card_type(card_number):
    # 根据BIN范围判断卡类型
    bin_ranges = {
        'Discover Card': [str(num) for num in range(622126, 622927)] + ['6011', '644', '649', '65'],
        'MasterCard': [str(num) for num in range(2221, 2721)] + ['51', '52', '53', '54', '55'],
        'JCB': [str(num) for num in range(3528, 3590)],
        'Switch': ['4903', '4905', '4911', '4936', '5641', '82', '6331', '6333', '6759'],
        'InstaPayment': ['636', '637', '638', '639'],
        'Laser': ['6304', '6706', '6771', '6709'],
        'Solo': ['6334', '6767'],
        'Diners Club Carte Blanche': ['300', '301', '302', '303', '304', '305'],
        'Diners Club enRoute': ['2014', '2149'],
        'American Express': ['34', '37'],
        'Diners Club International': ['36'],
        'China UnionPay': ['62'],
        'Maestro': ['50', '56', '57', '58'],
        'Visa': ['4'],
        'UATP': ['1']
    }
    
    # 将卡号的前六位转换为字符串
    card_bin = card_number[:6]
    
    # 检查卡号的前六位是否在任何已知的BIN范围内
    for card_type, ranges in bin_ranges.items():
        if any(card_bin.startswith(range) for range in ranges):
            return card_type
    
    # 如果卡号的前六位不在任何已知的BIN范围内，返回未知
    return 'Unknown'

# 示例使用
card_number_example = "4111111111111111"  # 示例Visa卡号
print(get_card_type(card_number_example))  # 输出: Visa