void setup()
{
  pinMode(23, OUTPUT);
  pinMode(22, OUTPUT);
  pinMode(21, OUTPUT);
}

void loop()
{
  digitalWrite(23, HIGH);
  digitalWrite(22, LOW);
  delay(1000); // Wait for 10000 millisecond(s)
  digitalWrite(21, HIGH);
  digitalWrite(23, LOW);
  delay(2000); // Wait for 2000 millisecond(s)
  digitalWrite(22, HIGH);
  digitalWrite(21, LOW);
  delay(5000); // Wait for 5000 millisecond(s)
}