const sumAll = function(num1, num2) {
    let final = 0;

    if (num1 < 0 || num2 < 0 || typeof num1 != 'number' || typeof num2 != 'number') {
        return "ERROR";
    } else if (num2 > num1) {
        for (let i = num1; i <= num2; i++) {
            final += i;
        }
    } else if (num1 > num2) {
        for (let i = num2; i <= num1; i++) {
            final += i;
        }
    } 

    return final;
};

// Do not edit below this line
module.exports = sumAll;