int LED1 = 13;
int LED2 = 12;
int LED3 = 11;
int LED4 = 10;

void setup() {
  // put your setup code here, to run once:
  pinMode(LED1,OUTPUT);
  pinMode(LED2,OUTPUT);
  pinMode(LED3,OUTPUT);
  pinMode(LED4,OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i=0; i<2; i++)
  {
    digitalWrite(LED1,HIGH);
    digitalWrite(LED2,HIGH);
    delay(1000);
    digitalWrite(LED1,LOW);
    digitalWrite(LED2,LOW);
    delay(1000);
  }
    digitalWrite(LED3,HIGH);
    delay(1000);
    digitalWrite(LED3,LOW);
    delay(1000);
    digitalWrite(LED4,HIGH);
    delay(1000);
    digitalWrite(LED4,LOW);
    delay(1000);  

}