64. Interrupt Operation

After uploading the following code to an Arduino UNO, what will happen when the push-button connected to pin 2 is pressed multiple times?

Note: Consider no noise is created from button press.

Code

#define BUTTON_PIN 2
#define LED 12

void INT0_ISR() {
  digitalWrite(LED, !digitalRead(LED));
  cli();   // Disable global interrupts
}

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);  // Enable internal pull-up resistor for INT0 pin
  pinMode(LED, OUTPUT);

  // Attach INT0 interrupt (pin 2) with falling edge trigger
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), INT0_ISR, FALLING);
  sei();  // Enable global interrupts
}

void loop() {
}