const int led1pin=13;
const int led2pin=12;
const int led3pin=11;
void setup() {
  // put your setup code here, to run once:
pinMode(led1pin, OUTPUT);
pinMode(led2pin, OUTPUT);
pinMode(led3pin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(led1pin, HIGH);
delay(2000);
digitalWrite(led1pin, LOW);
delay(500);
digitalWrite(led2pin, HIGH);
delay(500);
digitalWrite(led2pin, LOW);
delay(1000);
digitalWrite(led3pin, HIGH);
delay(1000);
digitalWrite(led3pin, LOW);
delay(500);
}