function solution(numbers) {
var answer = [];
let sum = 0;
//numbers배열 다 돌면서
for (let i = 0; i < numbers.length; i++) {
for (let j = i + 1; j < numbers.length; j++) {
sum = numbers[i] + numbers[j];
if (!answer.includes(sum)) answer.push(sum);
}
}
//오름차순 정렬
answer.sort((a, b) => a - b);
return answer;
}