int i ;

void setup() 

{
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);

  pinMode(2, INPUT_PULLUP);
  attachInterrupt(0,LEDV,LOW);

}

void loop() {

  for (i=1;i<1000;i++){

digitalWrite(8, HIGH);
  delay(500);
digitalWrite(8, LOW);
delay(500);
  }
}

void LEDV(){
digitalWrite(9, HIGH);

digitalWrite(9, LOW);

}