import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class minimumMaximum {
    public static void main(String[] args) {

        // Creates a scanner object
        Scanner inputExpression = new Scanner(System.in);
        // Reads user input
        String input = inputExpression.nextLine();
        // Splits input into an array of character strings
        String[] exp = input.split("");
        // checks for errors
        errorCheck(exp);
        // PRINTS FINAL OUTPUT
        System.out.println(calculation(combineNums(exp)));

    }

    // Performs primary calculation
    public static Integer calculation(String[] inputExp) {
        // GETS RID OF PARENS
        ArrayList<String> fullExp = new ArrayList<>(Arrays.asList(deleteParens(inputExp)));

        // BASE CASE 1
        if (fullExp.size() == 1) {
            return Integer.parseInt(fullExp.get(0));
        // BASE CASE 2
        } else if (deleteParens(fullExp.toArray(new String[fullExp.size()])).length == 1) {

            return Integer.parseInt(fullExp.get(1));


        // RECURSIVE CASE
        } else {


            // Loops thru the full expression
            for (int i = 0; i < (fullExp.size()); i++) {

                // Performs min (@) calculation

                if (isInt(fullExp.get(i)) && isInt(fullExp.get(i + 2)) && fullExp.get(i + 1).equals("@")) {
                    Integer a = Integer.parseInt(fullExp.get(i));
                    Integer b = Integer.parseInt(fullExp.get(i + 2));
                    Integer minResult = minOperator(a, b);
                    fullExp.set(i, Integer.toString(minResult));
                    fullExp.remove(i+2);
                    fullExp.remove(i+1);

                    return calculation(deleteParens(fullExp.toArray(new String[fullExp.size()])));


                    // Performs max (&) calculation
                } else if (isInt(fullExp.get(i)) && isInt(fullExp.get(i + 2)) && fullExp.get(i + 1).equals("&")) {
                    Integer a = Integer.parseInt(fullExp.get(i));
                    Integer b = Integer.parseInt(fullExp.get(i + 2));
                    Integer maxResult = maxOperator(a, b);
                    fullExp.set(i, Integer.toString(maxResult));
                    fullExp.remove(i+2);
                    fullExp.remove(i+1);
                    return calculation(deleteParens(fullExp.toArray(new String[fullExp.size()])));

                }


            }

            // Indicates error if run
            return 99999999;

        }

    }

    // Creates the "@" operator which takes in two integers and returns the minimum
    public static Integer minOperator(Integer a, Integer b) {
        if (a < b) {
            // "a" is the min
            return a;
        } else if (b < a) {
            // "b" is the min
            return b;
        } else {
            // "a" and "b" are the same, return either
            return a;
        }
    }


    // Creates the "&" operator which takes in two integers and returns the minimum
    public static Integer maxOperator(Integer a, Integer b) {
        if (a > b) {
            // "a" is the max
            return a;
        } else if (b > a) {
            // "b" is the max
            return b;
        } else {
            // "a" and "b" are the same, return either
            return a;
        }
    }

    // combine numbers
    public static String[] combineNums(String[] arrInput) {
        // converting to array list
        ArrayList<String> rawInput = new ArrayList<>(Arrays.asList(arrInput));

        for (int i = 0; i < rawInput.size(); i++) {
            if (isInt(rawInput.get(i))) {
                String newNum = rawInput.get(i);
                int counter = 1;

                if (i == rawInput.size()-1) {
                    break;
                } else if (i + counter == rawInput.size()-1) {
                    if (isInt(rawInput.get(i + counter))) {
                        newNum = newNum.concat(rawInput.get(i + counter));
                        counter++;
                    } else {
                        rawInput.remove(rawInput.size()-2);
                        break;
                    }
                } else {
                    while (isInt(rawInput.get(i + counter))) {
                        newNum = newNum.concat(rawInput.get(i + counter));

                        if (i + counter + 1 == rawInput.size() - 1) {
                            if (isInt(rawInput.get(i + counter + 1))) {
                                newNum = newNum.concat(rawInput.get(i + counter + 1));
                                counter += 2;
                                break;
                            }
                            break;
                        } else {
                            counter++;
                        }
                    }
                }

                rawInput.set(i, newNum);
                rawInput.subList(i+1, i+counter).clear();
            }

        }

        return rawInput.toArray(new String[rawInput.size()]);
    }


    public static boolean isInt(String str) {
        if (str.matches("\\d+")) {
            return true;
        } else {
            return false;
        }
    }

    public static String[] deleteParens(String[] arr) {
        ArrayList<String> arrInput = new ArrayList<>(Arrays.asList(arr));

        for (int i = 0; i < arrInput.size()-2; i++) {
            if (arrInput.get(i).equals("(") && isInt(arrInput.get(i + 1)) && arrInput.get(i + 2).equals(")")) {
                arrInput.remove(i+2);
                arrInput.remove(i);
            }
        }
        return arrInput.toArray(new String[arrInput.size()]);
    }

    // ERROR CHECKERS
//    public static void errorCheck(String input) {
//        if (input.length() > 1000) {
//            System.out.println("INVALID EXPRESSION");
//            System.exit(0);
//        } else if (input.length() - input.replace("(", "").length() != input.length() - input.replace(")", "").length()) {
//            System.out.println("INVALID EXPRESSION");
//            System.exit(0);
//        }
//    }

    public static void errorCheck(String[] inputL) {
        for (String c : inputL){
            if (!(isInt(c)) && !(c.equals("(")) && !(c.equals(")")) && !(c.equals("@")) && !(c.equals("&"))){
                System.out.println("INVALID CHARACTERS");
                System.exit(0);
            }
        }

        if (inputL.length > 1000) {
            System.out.println("INVALID EXPRESSION");
            System.exit(0);
        } else if (Arrays.toString(inputL).length() - Arrays.toString(inputL).replace("(", "").length() != Arrays.toString(inputL).length() - Arrays.toString(inputL).replace(")", "").length()) {
            System.out.println("INVALID EXPRESSION");
            System.exit(0);
        }


        for (int i = 0; i < (inputL.length - 1); i++) {
            if (inputL[i].equals(inputL[i + 1])) {  // checks for "@@" or "&&" in user's input
                if (!(inputL[i].equals("(")) && !(inputL[i].equals(")")) && !(isInt(inputL[i]))) {
                    System.out.println("INVALID EXPRESSION");
                    System.exit(0);
                }
            } else if (inputL[i].equals("@") && inputL[i + 1].equals("&")) {  // checks for "@&" in user's input
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i].equals("&") && inputL[i + 1].equals("@")) {  // checks for "&@" in user's input
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i + 1].equals("&") && (i + 1 == inputL.length - 1)) {  // checks if last character is &
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i + 1].equals("@") && (i + 1 == inputL.length - 1)) {  // checks if last character is @
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i].equals("&") && (i == 0)) {  // checks if first character is &
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i].equals("@") && (i == 0)) {  // checks if first character is @
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            } else if (inputL[i].equals("(") && inputL[i + 1].equals(")")) {  // checks for cases of empty brackets "()"
                System.out.println("INVALID EXPRESSION");
                System.exit(0);
            }
        }
    }
}