int D7 = 7;
int D6 = 6;
int D5 = 5;
int D4 = 4;
int D3 = 3;
int D2 = 2;

void setup() {
  pinMode(D7, OUTPUT);
  pinMode(D6, OUTPUT);
  pinMode(D5, OUTPUT);
  pinMode(D4, OUTPUT);
  pinMode(D3, OUTPUT);
  pinMode(D2, OUTPUT);

}

void loop() {
  ryg(D2, D6, D7);
  ryg(D5, D3, D4);
}

void ryg(int red, int yellow, int green){
  digitalWrite(red, HIGH);
  digitalWrite(green, HIGH);
  delay(4000);
  digitalWrite(red, LOW);
  digitalWrite(green, LOW);
  digitalWrite(yellow, HIGH);
  delay(1000);
  digitalWrite(yellow, LOW);
}