const int redpin = 13;
 const int greenpin = 10;
const int bluepin = 8;
void setup() {
  pinMode(redpin, OUTPUT);
  pinMode(greenpin, OUTPUT);
  pinMode(bluepin, OUTPUT);
}

void loop() {
  digitalWrite(redpin, HIGH);
  delay(3000);
  digitalWrite(redpin, LOW);
  digitalWrite(greenpin, HIGH);
  delay(3000);
   digitalWrite(greenpin, LOW);
  digitalWrite(bluepin, HIGH);
  delay(3000);
  digitalWrite(bluepin, LOW);
}