Dance Hall

function danceHall(input) {
    let length = Number(input.shift());
    let width = Number(input.shift());
    let wardrobeSide = Number(input.shift());

    let hallArea = length * width;
    let wardrobeArea = wardrobeSide ** 2;
    let benchArea = hallArea * 0.1;

    let freeArea = hallArea - wardrobeArea - benchArea;
    let dancerArea = (40 + 7000) / 10000;

    let result = Math.floor(freeArea / dancerArea);
    console.log(result);
}