void setup() {
  pinMode(2,OUTPUT);
  pinMode(3,OUTPUT);
  pinMode(4,OUTPUT);
  pinMode(5,OUTPUT);
  pinMode(6,OUTPUT);
  // put your setup code here, to run once:

}

void loop() 
{

for(int a = 2;a<=6;a++)
{
  digitalWrite(a,LOW); 
  digitalWrite(a,HIGH); 
  delay(500);
}


}