int redPin=13;
int bluPin=12;
int grnPin=11;
int ylwPin=10;
int t=400;

void setup() {
  // put your setup code here, to run once:
pinMode(redPin,OUTPUT);
pinMode(bluPin,OUTPUT);
pinMode(grnPin,OUTPUT);
pinMode(ylwPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(redPin,LOW);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,HIGH);
delay(t);
digitalWrite(ylwPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,HIGH);
digitalWrite(ylwPin,LOW);
delay(t);
digitalWrite(grnPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,HIGH);
digitalWrite(ylwPin,HIGH);
delay(t);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,HIGH);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,LOW);
delay(t);
digitalWrite(bluPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,HIGH);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,HIGH);
delay(t);
digitalWrite(bluPin,LOW);
digitalWrite(ylwPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,HIGH);
digitalWrite(grnPin,HIGH);
digitalWrite(ylwPin,LOW);
delay(t);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,LOW);

delay(t);
digitalWrite(redPin,LOW);
digitalWrite(bluPin,HIGH);
digitalWrite(grnPin,HIGH);
digitalWrite(ylwPin,HIGH);
delay(t);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,LOW);

delay(t);
digitalWrite(redPin,HIGH);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,LOW);
delay(t);
digitalWrite(redPin,LOW);

delay(t);
digitalWrite(redPin,HIGH);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,LOW);
digitalWrite(ylwPin,HIGH);
delay(t);
digitalWrite(redPin,LOW);
digitalWrite(ylwPin,LOW);

delay(t);
digitalWrite(redPin,HIGH);
digitalWrite(bluPin,LOW);
digitalWrite(grnPin,HIGH);
digitalWrite(ylwPin,LOW);
delay(t);
digitalWrite(redPin,LOW);
digitalWrite(grnPin,LOW);
delay(t);

}