int t=200;

void setup() {
 pinMode(9, INPUT);
 pinMode(10, INPUT);
 pinMode(11, INPUT);
 pinMode(12, INPUT);

}

void loop() {
  digitalWrite(9, HIGH);
  digitalWrite(10, LOW);
  digitalWrite(11, LOW);
    digitalWrite(12, LOW);
  delay(t);
  digitalWrite(9, LOW);
  digitalWrite(10, HIGH);
  digitalWrite(11, LOW);
    digitalWrite(12, LOW);
  delay(t);
  digitalWrite(9, LOW);
  digitalWrite(10, LOW);
  digitalWrite(11, HIGH);
  digitalWrite(12, LOW);  
  delay(t);
  digitalWrite(9, LOW);
  digitalWrite(10, LOW);
  digitalWrite(11, LOW);
    digitalWrite(12, HIGH);
  delay(t);
}