what resistor should I be using for these 12v 50mA momentary buttons for my Ar3

Other Hardware Product Design
2

This is an example Arduino code to use the read the button and execute the servo motor when button is pressed.

const int IButton = 10; //Idle speed button

pinMode(IButton, INPUT);

IBState = digitalRead(IButton); // read the state of the Idle pushbutton value

if (IBState == HIGH) { // run the Idle speed function
delay(250); // to debounce button
Idle(); // go to Idle function
}

My guess is I can use 10K ohm resistor as well as the Arduino R3 internal pull-up resistor too.