function solution(lines) {
var answer = 0;
const arr = Array.from({ length: 200 }, (_, index) => 0);
for (let i = 0; i < lines.length; i++) {
let startPos = lines[i][0] + 100;
let endPos = lines[i][1] + 100;
for (let j = startPos; j < endPos; j++) {
arr[j] += 1;
}
}
return arr.filter((number) => number >= 2).length;
}