Android studio - exp4j - problem with Equal

I want to create Calculator Application, and I just want to make Equal function with exp4j that will calculate string of characters, but I have problem with this.

I don't know exp4j too much and I just don't what to changa, or add to work propertly.

bEqual.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                calculations = input.getText().toString();

                try {
                    Expression expression = new ExpressionBuilder(calculations).build();
                    double result = expression.evaluate();

                    output.setText((int) result);

                }catch (Exception e){
                    System.out.println("Message: "+e.getMessage());
                }
            }
        });

E/example.fizcal: Invalid ID 0x0000000e.
I/System.out: Message: String resource ID #0xe
E/example.fizcal: Invalid ID 0x00000009.
I/System.out: Message: String resource ID #0x9
E/example.fizcal: Invalid ID 0x00000291.
I/System.out: Message: String resource ID #0x291
E/example.fizcal: Invalid ID 0x00000291.
I/System.out: Message: String resource ID #0x291
E/example.fizcal: Invalid ID 0x00000291.
I/System.out: Message: String resource ID #0x291
E/example.fizcal: Invalid ID 0x00000291.
I/System.out: Message: String resource ID #0x291
E/example.fizcal: Invalid ID 0x00000291.
I/System.out: Message: String resource ID #0x291