function solution(n, lost, reserve) {
var answer = 0
lost.sort()
reserve.sort()
let arr = new Array(n).fill(1)
for (let i = 0; i < lost.length; i++) {
arr[lost[i] - 1] -= 1
}
for (let i = 0; i < reserve.length; i++) {
arr[reserve[i] - 1] += 1
}
for (let i = 0; i < n - 1; i++) {
if (
(arr[i] === 0 && arr[i + 1] === 2) ||
(arr[i] === 2 && arr[i + 1] === 0)
) {
arr[i] = 1
arr[i + 1] = 1
}
}
arr.map((v) => (v !== 0 ? answer++ : answer))
return answer
}
solution(5, [2, 4], [3])