from functools import cmp_to_key


li = [32, 94, 128, 1286, 6, 71]


def xy_cmp(x, y):

    # x 小的话，return 1：需要交换
    if x + y < y + x:
        return 1
    elif x + y > y + x:
        return -1
    else:
        return 0


def number_join(li):
    """数字拼接"""

    li = list(map(str, li))
    li.sort(key=cmp_to_key(xy_cmp))
    return ''.join(li)