const adSpam = (n) => {
    let cumulative = 0;
    let shared = 5;
    let liked = 0;
    for (let i = 1; i <= n; i++) {
        liked = Math.floor(shared / 2)
        shared = liked * 3
        cumulative += liked
    }

    return cumulative;
}

console.log(adSpam(3))