////////////
function left(a, b, c) {
    const result = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
    if (result > 0) return -1;
    else if (result < 0) return 1;
    else return 0;
}
////////////

points.sort((a, b) => a.y - b.y);
const startPoint = points.shift();

points.sort((a, b) => left(startPoint, a, b));
points.unshift(startPoint);

const N = points.length;
let stack = new Array();

stack.push(points[0]);
stack.push(points[1]);
stack.push(points[2]);

for (let i = 3; i < N; i++) {
    let top = stack.pop();
    while (left(stack[stack.length - 1], top, points[i]) != -1) {
        top = stack.pop();
    }
    stack.push(top);
    stack.push(points[i]);
}