int G1 = 0, Y1 = 1, R1 = 2;
int G2 = 3, Y2 = 4, R2 = 5;
int G3 = 6, Y3 = 7, R3 = 8;
int G4 = 9, Y4 = 10, R4 = 11;

 void setup() {
  // put your setup code here, to run once:

  pinMode(G1, OUTPUT);
  pinMode(Y1, OUTPUT);
  pinMode(R1, OUTPUT);
  pinMode(G2, OUTPUT);
  pinMode(Y2, OUTPUT);
  pinMode(R2, OUTPUT);
  pinMode(G3, OUTPUT);
  pinMode(Y3, OUTPUT);
  pinMode(R3, OUTPUT);
  pinMode(G4, OUTPUT);
  pinMode(Y4, OUTPUT);
  pinMode(R4, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(G1, HIGH);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, LOW);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(2000);
  //step2
  digitalWrite(G1, LOW);
  digitalWrite(Y1, HIGH);
  digitalWrite(R1, LOW);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  //step3
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  //step4
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, HIGH);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, LOW);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(2000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, HIGH);
  digitalWrite(R2, LOW);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, HIGH);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, LOW);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(2000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, HIGH);
  digitalWrite(R3, LOW);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, HIGH);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, LOW);
  delay(2000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, HIGH);
  digitalWrite(R4, LOW);
  delay(1000);
  digitalWrite(G1, LOW);
  digitalWrite(Y1, LOW);
  digitalWrite(R1, HIGH);
  digitalWrite(G2, LOW);
  digitalWrite(Y2, LOW);
  digitalWrite(R2, HIGH);
  digitalWrite(G3, LOW);
  digitalWrite(Y3, LOW);
  digitalWrite(R3, HIGH);
  digitalWrite(G4, LOW);
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  delay(1000);


}