#define red 10
#define green 11
#define yellow 12
 value valuevoid setup() 
 {
  pinMode(red,OUTPUT);
  pinMode(green,OUTPUT);
  pinMode(yellow,OUTPUT);
  Serial.begin(9600)
}

void loop() 
{
 digitalWrite(red,HIGH);
 digitalWrite(green,LOW);
 digitalWrite(yellow,LOW);

 digitalWrite(red,LOW);
 digitalWrite(green, HIGH);
 digitalWrite(yellow, LOW);

 digitalWrite(red,LOW);
 digitalWrite(green,LOW);
 digitalWrite(yellow, HIGH);
}