int red_led = 8, yellow_led = 7, green_led = 6;
bool bleank = 0;

void setup() {
  pinMode(red_led, OUTPUT);
  pinMode(yellow_led, OUTPUT);
  pinMode(green_led, OUTPUT);
  digitalWrite(red_led, LOW);
  digitalWrite(yellow_led, LOW);
  digitalWrite(green_led, LOW);

}

void loop() {
digitalWrite(red_led, HIGH);
delay(5000);

digitalWrite(yellow_led, HIGH);
delay(2000);

digitalWrite(red_led, LOW);
digitalWrite(yellow_led, LOW);
digitalWrite(green_led, HIGH);
delay(5000);

for(int i=0; i>5 ;i++){
  bleank != bleank;
  digitalWrite(green_led, bleank);
  delay(700);
}

digitalWrite(green_led, LOW);
digitalWrite(yellow_led, HIGH);
delay(3000);

digitalWrite(yellow_led, LOW);
}