int rl = 4;
int bl = 2;
int pl = 7;
int yl = 8;

int del = 1000; 

void setup() {
  // put your setup code here, to run once:
pinMode(rl, OUTPUT);
pinMode(bl, OUTPUT);
pinMode(pl, OUTPUT);
pinMode(yl, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:

digitalWrite(rl, LOW);
digitalWrite(bl, LOW);
digitalWrite(pl, LOW);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, LOW);
digitalWrite(pl, LOW);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, HIGH);
digitalWrite(pl, LOW);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, HIGH);
digitalWrite(pl, LOW);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, LOW);
digitalWrite(pl, HIGH);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, LOW);
digitalWrite(pl, HIGH);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, HIGH);
digitalWrite(pl, HIGH);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, HIGH);
digitalWrite(pl, HIGH);
digitalWrite(yl, LOW);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, LOW);
digitalWrite(pl, LOW);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, LOW);
digitalWrite(pl, LOW);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, HIGH);
digitalWrite(pl, LOW);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, HIGH);
digitalWrite(pl, LOW);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, LOW);
digitalWrite(pl, HIGH);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, LOW);
digitalWrite(pl, HIGH);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, LOW);
digitalWrite(bl, HIGH);
digitalWrite(pl, HIGH);
digitalWrite(yl, HIGH);
delay(del);

digitalWrite(rl, HIGH);
digitalWrite(bl, HIGH);
digitalWrite(pl, HIGH);
digitalWrite(yl, HIGH);
delay(del);
}