Guinea Pig

function demo(input) {


    let [food, hay, cover, weight] = input;


    let foodGr = food * 1000;

    let hayGr = hay * 1000;

    let coverGr = cover * 1000;

    let weightGr = weight * 1000;

    let days = 1;


    while (days <= 30) {

        foodGr -= 300;

        if (days % 2 === 0) {

            hayGr -= (foodGr * 5) / 100;

        }

        if (days % 3 === 0) {

            coverGr -= weightGr * 0.3333;
        }

        days++;

    }

    let foodKg = foodGr / 1000;

    let hayKg = hayGr / 1000;

    let coverKg = coverGr / 1000;


    if (foodKg >= 0 && hayKg >= 0 && coverKg >= 0) {

        console.log(`Everything is fine! Puppy is happy! Food: ${foodKg.toFixed(2)}, Hay: ${hayKg.toFixed(2)}, Cover: ${coverKg.toFixed(2)}.`)


    } else if (foodKg < 0 || hayKg < 0 || coverKg < 0) {

        console.log('Merry must go to the pet store!')
    }
}