function polishNotation(operators) {
    const numbers = [];
    const actions = {
        '+':(a, b) => a + b,
        '-':(a, b) => a - b,
        '*':(a, b) => a * b,
        '/':(a, b) => a / b,
    };
    for (let i = 0; i < operators.length; i += 1) {
        if(Number(operators[i])) {
            numbers.push(Number(operators[i]));
        } else {
            const secondNum = numbers.pop();
            const firstNum = numbers.pop();
            numbers.push(actions[operators[i]](firstNum,secondNum))
        }
    }
    return numbers;
}