"""
출처: 프로그래머스 코딩 테스트 연습,
https://school.programmers.co.kr/learn/courses/30/lessons/120863
"""

# 풀이 과정

def solution(polynomial):
    x = polynomial.split()
    list_x = []
    count = 0

    for a in range(len(x)):
        if "x" in x[a]:
            list_x.append(x[a])
        elif "+" in x[a]:
            continue
        else:
            count += int(x[a])

    for b in range(len(list_x)):
        if list_x[b] == "x":
            list_x[b] = 1
        else:
            list_x[b] = int(list_x[b][0:len(list_x[b]) - 1])
    if count == 0 and not sum(list_x) == 0 and not sum(list_x) == 1:
        return str(sum(list_x)) + "x"
    elif count == 0 and sum(list_x) == 0:
        return 0
    elif not count == 0 and sum(list_x) == 0:
        return str(count)
    elif not count == 0 and sum(list_x) == 1:
        return "x " + "+ " + str(count)
    elif count == 0 and sum(list_x) == 1:
        return "x"
    else:
        return str(sum(list_x)) + "x " + "+ " + str(count)