int REDLED1=2;
int GREENLED2=3;
int ORANGELED3=4;
void setup()
{
  pinMode(REDLED1,OUTPUT);
  pinMode(GREENLED2,OUTPUT);
  pinMode(ORANGELED3,OUTPUT);
}
void loop()
{
  digitalWrite(GREENLED2,LOW);
  digitalWrite(ORANGELED3,LOW);
  digitalWrite(REDLED1,HIGH);
  delay(15000);
   digitalWrite(ORANGELED3,LOW);
   digitalWrite(REDLED1,LOW);
   digitalWrite(GREENLED2,HIGH);
   delay(7000);
   digitalWrite(REDLED1,LOW);
   digitalWrite(GREENLED2,LOW);
   digitalWrite(ORANGELED3,HIGH);
    delay(15000);
}