function solve(arr) {


  let price = 0;

  let oneGramGoldPrice = 67.51;

  let bitcoinPrice = 11949.16;

  let countBitc = 0;

  let dayOfFirstBuy = 0;

  let counter = 0;

  let moneyLeft = 0;

  let goldGrams = 0;

  let counter2 = 0;



  for (gold of arr) {


    counter2++;

    if (counter2 % 3 === 0) {

      goldGrams = gold;

      goldGrams = goldGrams - goldGrams * (30 / 100);

      price += goldGrams * oneGramGoldPrice;

    } else {

      price += gold * oneGramGoldPrice;

    }


    while (bitcoinPrice <= price) {

      moneyLeft = price - bitcoinPrice;

      price = moneyLeft;



      if (counter === 0) {

        counter++;

        dayOfFirstBuy = counter2;

      }

      countBitc++;

    }

  }


  if (counter === 0) {

    moneyLeft = price;

  }


console.log(`Bought bitcoins: ${countBitc}`);

if (counter > 0) {

console.log(`Day of the first purchased bitcoin: ${dayOfFirstBuy}`);

}

console.log(`Left money: ${moneyLeft.toFixed(2)} lv.`);

    // 10531.78 lv.


}