#define LED_PIN 12
#define BUTTON_PIN 9
  
unsigned int button_status = 0;
 
boolean isAllowed = true; 
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
}
 
void loop() {
 
  button_status = digitalRead(BUTTON_PIN);
 
  if (isAllowed){
    if (button_status == 0) {
      digitalWrite(LED_PIN, LOW);
    } else {
      digitalWrite(LED_PIN, HIGH);
      delay(3500);
      isAllowed = false;
    }
  }else{
    digitalWrite(LED_PIN, LOW);
    if (button_status == 0){
      isAllowed = true;
    }
  }  
}