65. Interrupt Conditions

Consider the following waveform and Arduino code.
How many times will the interrupt be triggered after applying the below signal on pin 3 of Arduino UNO (INT1)?

Code

#include <avr/interrupt.h>
void setup() {
  pinMode(3, INPUT_PULLUP);  // Set pin 8 as input with internal pull-up
  attachInterrupt(digitalPinToInterrupt(3), ISR_INT1, RISING);
}
void loop() {
  // Main loop does nothing, all handled by interrupts
}
void ISR_INT1() {
   
}