```python
# -*- coding: utf-8 -*-
# @Time    : 2020/7/15 12:45
# @Author  : lagelanren
# @Email   : forhaogege@163.com
# @File    : what_is_elegance.py
# @Software: PyCharm
def main():
    answer = [0]*10
    answer_letter = []
    while(answer[-1]!=4):
        #开始构造答案
        a = b = c = d = 0
        for k,i in enumerate(answer):
            if i == 4:
                answer[k] = 0
                answer[k+1] += 1
                break
        else:
            answer[0] += 1
        if 4 not in answer:
            #答案丢进去试
            for i in answer:
                if i == 0:
                    a += 1
                if i == 1:
                    b += 1
                if i == 2:
                    c += 1
                if i == 3:
                    d += 1
            for k,less in enumerate([a,b,c,d]):
                if less == min(a,b,c,d):
                    if k == 0:
                        less = 0
                    if k == 1:
                        less = 1
                    if k == 2:
                        less = 2
                    if k == 3:
                        less = 3
                    break
            if (answer[1] == 0 and answer[4] == 2) or (answer[1] == 1 and answer[4] == 3) or (answer[1] == 2 and answer[4] == 0) or (answer[1] == 3 and answer[4] == 1):
                if answer[2] == 0 or answer[2] == 1 or answer[2] == 3:
                    if (answer[3] == 0 and answer[0] == answer[4]) or (answer[3] == 1 and answer[1] == answer[6]) or (answer[3] == 2 and answer[0] == answer[8]) or (answer[3] == 3 and answer[5] == answer[9]):
                        if (answer[4] == 0 and answer[7] == 0) or (answer[4] == 1 and answer[3] == 1) or (answer[4] == 2 and answer[8] == 2) or (answer[4] == 3 and answer[6] == 3):
                            if (answer[5] == 0 and answer[7] == answer[1] == answer[3]) or (answer[5] == 1 and answer[7] == answer[0] == answer[5]) or (answer[5] == 2 and answer[7] == answer[2] == answer[9]) or (answer[5] == 3 and answer[7] == answer[4] == answer[8]):
                                if (answer[6] == 0 and less == 2) or (answer[6] == 1 and less == 1) or (answer[6] == 2 and less == 0) or (answer[6] == 3 and less == 3):
                                    if (answer[7] == 0 and (answer[0]-answer[6] not in [1,-1])) or (answer[7] == 1 and (answer[0]-answer[5] not in [1,-1])) or (answer[7] == 2 and (answer[0]-answer[1] not in [1,-1])) or (answer[7] == 3 and (answer[0]-answer[9] not in [1,-1])):
                                       if answer[0] == answer[5]:
                                           if (answer[8] == 0 and (answer[5] != answer[4])) or (answer[8] == 1 and (answer[9] != answer[4])) or (answer[8] == 2 and (answer[1] != answer[4])) or (answer[8] == 3 and (answer[8] != answer[4])):
                                               if (answer[9] == 0 and (max(a,b,c,d) - min(a,b,c,d)) == 3) or (answer[9] == 1 and (max(a,b,c,d) - min(a,b,c,d)) == 2) or (answer[9] == 2 and (max(a,b,c,d) - min(a,b,c,d)) == 4) or (answer[9] == 3 and (max(a,b,c,d) - min(a,b,c,d)) == 1):
                                                   break
                                       if answer[0] != answer[5]:
                                           if (answer[8] == 0 and (answer[5] == answer[4])) or (answer[8] == 1 and (answer[9] == answer[4])) or (answer[8] == 2 and (answer[1] == answer[4])) or (answer[8] == 3 and (answer[8] == answer[4])):
                                               if (answer[9] == 0 and (max(a,b,c,d) - min(a,b,c,d)) == 3) or (answer[9] == 1 and (max(a,b,c,d) - min(a,b,c,d)) == 2) or (answer[9] == 2 and (max(a,b,c,d) - min(a,b,c,d)) == 4) or (answer[9] == 3 and (max(a,b,c,d) - min(a,b,c,d)) == 1):
                                                   break
    #答案成ABCD
    for k, i in enumerate(answer):
        k = str(k + 1)
        if i == 0:
            answer_letter.append(k + "A ")
        if i == 1:
            answer_letter.append(k + "B ")
        if i == 2:
            answer_letter.append(k + "C ")
        if i == 3:
            answer_letter.append(k + "D ")
    print(answer_letter)

if __name__ == '__main__':
    main()