const int redLight = 10;
const int yellowLight = 9;
const int greenLight = 8;

void setup() {
  // put your setup code here, to run once:
 pinMode(redLight,OUTPUT);
 pinMode(yellowLight,OUTPUT);
 pinMode(greenLight, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(redLight, HIGH);
delay(5000);
digitalWrite(redLight, LOW);


digitalWrite(yellowLight, HIGH);
delay(2000); 
digitalWrite(yellowLight, LOW);

digitalWrite(greenLight, HIGH);
delay(5000);  
digitalWrite(greenLight, LOW);
}