task3

        function Solve(args) {
            var func = {};
            var result = 0;
            for (var i = 0; i < args.length; i++) {
                while (args[i].match(/\(/g).length > 1) {
                    var startPosition = args[i].indexOf("(", args[i].indexOf("(") + 1);
                    var endPosition = args[i].indexOf(')', startPosition);
                    var value = calculate(args[i].substring(startPosition + 1, endPosition), func);
                    if (typeof (value) == "string") {
                        return "Division by zero! At Line:" + (i + 1);
                    }
                    args[i] = args[i].substring(0, startPosition) + ' ' + value + args[i].substring(endPosition + 1);
                }
                var startPosition = args[i].indexOf("(") + 1;
                var endPosition = args[i].indexOf(')');
                result = calculate(args[i].substring(startPosition, endPosition), func);
                if (typeof (result) == "string") {
                    return "Division by zero! At Line:" + (i + 1);
                }
            }
            return result;
        }

        function calculate(text, func) {
            var result = 0;
            var expressionWithEmpty = text.split(' ');
            var expression = [];
            for (var i = 0; i < expressionWithEmpty.length; i++) {
                if (expressionWithEmpty[i] != "") {
                    expression.push(expressionWithEmpty[i]);
                }
            }
            var start = 1;
            if (expression[0] == "def") {
                start = 2;
            }
            for (var i = start; i < expression.length; i++) {
                if (expression[i].match(/^[0-9]+$/)) {
                    expression[i] = parseInt(expression[i]);
                } else {
                    expression[i] = func[expression[i]];
                }
            }
            switch (expression[0]) {
                case "def":
                    func[expression[1]] = expression[2];
                    return;
                case "+":
                    for (var j = 1; j < expression.length; j++) {
                        result += expression[j];
                    }
                    break;
                case "-":
                    result = expression[1];
                    for (var j = 2; j < expression.length; j++) {
                        result -= expression[j];
                    }
                    break;
                case "*":
                    result = 1;
                    for (var j = 1; j < expression.length; j++) {
                        result *= expression[j];
                    }
                    break;
                case "/":
                    result = expression[1];
                    for (var j = 2; j < expression.length; j++) {
                        if (expression[j] == 0) {
                            return "Division by zero! At Line:";
                        }
                        result = parseInt(result / expression[j]);
                    }
                    break;
                default:
                    break;
            }
            return result;
        }