const byte LED = 8;        // Pin connected to the LED
const byte flash_button = 2; //Pin connected to the flash button (BLUE)
const byte turn_off_button = 12;//Pin connected to the turn off button (GREEN)

void setup() {
  pinMode(LED , OUTPUT);
  pinMode(flash_button, INPUT_PULLUP);
  pinMode(turn_off_button, INPUT_PULLUP);
}

void loop() {
  if ( digitalRead(turn_off_button) == LOW )  //GREEN preseed 
  {
    digitalWrite(LED , LOW); // LED is turned off until the  turn off button isreleased
  } 
  else if (digitalRead(flash_button) == LOW) // BLUE pressed
  {
    digitalWrite(LED , HIGH); //LED shines continuously until the flash button  is released
  } 
  else // blinking 500ms
  {
    digitalWrite(LED , HIGH);
    delay(500);
    digitalWrite(LED , LOW);
    delay(500);
  }
}