void setup() {
  // put your setup code here, to run once:
pinMode(2,INPUT_PULLUP); 
pinMode(13, OUTPUT);
pinMode(12, OUTPUT);
pinMode(11, OUTPUT);
Serial.begin(9600); 
}

void loop() {
 if (digitalRead(2)==0){
    digitalWrite(13, HIGH);
    delay(500);                 
    digitalWrite(12, HIGH);  
    delay(500);  
    digitalWrite(11, HIGH);  
    delay(500);
}else{
  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  digitalWrite(11, LOW);
}
}