#define ledred 13
#define ledblue 12
#define ledgreen 14
#define ledyellow 27

void setup() {
pinMode(ledred, OUTPUT);
pinMode(ledblue, OUTPUT);
pinMode(ledgreen, OUTPUT);
pinMode(ledyellow, OUTPUT);
}

void loop() {
digitalWrite(ledred, HIGH);
digitalWrite(ledblue, LOW);
digitalWrite(ledgreen, LOW);
digitalWrite(ledyellow, LOW);
delay(500);
digitalWrite(ledred, LOW);
digitalWrite(ledblue, HIGH);
digitalWrite(ledgreen, LOW);
digitalWrite(ledyellow, LOW);
delay(500);
digitalWrite(ledred, LOW);
digitalWrite(ledblue, LOW);
digitalWrite(ledgreen, HIGH);
digitalWrite(ledyellow, LOW);
delay(500);
digitalWrite(ledred, LOW);
digitalWrite(ledblue, LOW);
digitalWrite(ledgreen, LOW);
digitalWrite(ledyellow, HIGH);
delay(500);

}