题解 | #数据分类处理#

from math import inf
import sys

# I = [int(i) for i in input().split(' ')[1:]]
I = input().split(' ')[1:]
R = [int(i) for i in input().split(' ')[1:]]
R = list(set(R))
R.sort()
all_number = []
for i in R:
    number_list = []
    c_I = I[:]
    for p_index in range(len(I)):
        p = I[p_index]
        if str(i) in p:
            number_list.append([p_index,int(p)])
            # number_list.append(int(p))
            # c_I.remove(p)
    # try:
    #     while 1:
    #         number_list.append(I[I.index(i)])
    #         del(I[I.index(i)])
    # except:
    if len(number_list) > 0:
        all_number.append(i)
        all_number.append(len(number_list))
        # number_list = sorted(number_list,key=lambda x:x[1],reverse=False)
        for n_index in range(len(number_list)):
            # all_number[0] += 1
            all_number.append(number_list[n_index][0])
            all_number.append(number_list[n_index][1])
print(len(all_number),end=' ')
for i in all_number:
    print(i,end=' ')