Ошибка: Exception in thread "main" java.util.NoSuchElementException

Помогите пожалуйста решить проблему. Во время исполнения программы у меня возникает такая ошибка:

For input string: "5+5"Exception in thread "main" java.util.NoSuchElementException
    at java.util.ArrayDeque.removeFirst(ArrayDeque.java:285)
    at java.util.ArrayDeque.pop(ArrayDeque.java:522)
    at com.company.awlmax.Compute.calculate(Compute.java:45)
    at com.company.awlmax.Main.main(Main.java:16)

В коде:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) {
        Compute compute = new Compute();
        try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
            String strInputInt;
            System.out.print("Input: ");
            strInputInt = br.readLine();
            System.out.print(Compute.calculate(strInputInt));
        } catch (IOException ex) {
            System.out.print(ex.getMessage());
        }
    }
}

И

import java.util.ArrayDeque;
import java.util.Deque;
import java.util.StringTokenizer;

public class Compute {
    public static Integer calculate(String strInputInt) {
        int iFirst = 0, iLast = 0;
        String sTemp;
        Deque<Integer> stack = new ArrayDeque<Integer>();
        StringTokenizer tokenizer = new StringTokenizer(strInputInt);
        while (tokenizer.hasMoreTokens()) {
            try {
                sTemp = tokenizer.nextToken().trim();
                if (1 == sTemp.length() && isInputOperator(sTemp.charAt(0))) {
                    iFirst = stack.pop();
                    iLast = stack.pop();
                    switch (sTemp.charAt(0)) {
                        case '+':
                            iFirst += iLast;
                            break;
                        case '-':
                            iFirst -= iLast;
                            break;
                        case '*':
                            iFirst += iLast;
                            break;
                        case '/':
                            iFirst += iLast;
                            break;
                        default:
                            throw new Exception("Nan " + sTemp);
                    }
                    stack.push(iFirst);
                } else {
                    iFirst = Integer.parseInt(sTemp);
                    stack.push(iFirst);
                }
            } catch (Exception ex) {
                System.out.print(ex.getMessage());
            }
        }
        return stack.pop();
    }


    private static boolean isInputOperator(char cAtrib) {
        switch (cAtrib) {
            case '+':
            case '-':
            case '*':
            case '/':
                return true;
        }
        return  false;
    }
}