int ledPin1 = 4;
int ledPin2 = 27;
int ledPin3 = 26;
int ledPin4 = 2;
void setup() {
  // put your setup code here, to run once:
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(ledPin4, OUTPUT);
}
void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(ledPin1, LOW);
  digitalWrite(ledPin2, LOW);
  digitalWrite(ledPin3, LOW);
  digitalWrite(ledPin4, LOW);
  delay(500);
  digitalWrite(ledPin2, HIGH);
  delay(500);
  digitalWrite(ledPin2, LOW);
  delay(500);
  digitalWrite(ledPin3, HIGH);
  delay(500);
  digitalWrite(ledPin3, LOW);
  delay(500);
  digitalWrite(ledPin4, HIGH);
  delay(500);
  digitalWrite(ledPin4, LOW);
  delay(500);
  digitalWrite(ledPin1, HIGH);
  delay(500);
  digitalWrite(ledPin1, LOW);
  delay(500);
  digitalWrite(ledPin1, LOW);
  digitalWrite(ledPin2, LOW);
  digitalWrite(ledPin3, LOW);
  digitalWrite(ledPin4, LOW);
  delay(500);
  digitalWrite(ledPin1, HIGH);
  delay(500);
  digitalWrite(ledPin1, LOW);
  delay(500);
  digitalWrite(ledPin4, HIGH);
  delay(500);
  digitalWrite(ledPin4, LOW);
  delay(500);
  digitalWrite(ledPin3, HIGH);
  delay(500);
  digitalWrite(ledPin3, LOW);
  delay(500);
  digitalWrite(ledPin2, HIGH);
  delay(500);
  digitalWrite(ledPin2, LOW);
  delay(500);
}