//Trafic Light signal;
void setup()
{
pinMode(13,OUTPUT);
pinMode(11,OUTPUT);
pinMode(12,OUTPUT);

String s="yellow";
if(s=="red")
{
  digitalWrite(13,HIGH);
  digitalWrite(12,LOW);
  digitalWrite(11,LOW);
  
}
else if (s=="yellow")
{
    digitalWrite(13,LOW);
  digitalWrite(12,HIGH);
  digitalWrite(11,LOW);
}
else if (s=="green")
{
   digitalWrite(13,LOW);
  digitalWrite(12,LOW);
  digitalWrite(11,HIGH);
}
}
void loop(){

}