[프로그래머스][Python] 두 개 뽑아서 더하기

def solution(numbers):
    answer=[]
    for i in range(len(numbers)):
        for j in range(i+1,len(numbers)):
            if numbers[i] + numbers[j] not in answer:
                answer.append(numbers[i]+numbers[j])
        answer.sort()
    return answer