const int lad1 = 7;
 const int lad2 = 6;


void setup() 
{ 
 pinMode(lad1 ,OUTPUT);
 pinMode(lad2 , OUTPUT);
  // put your setup code here, to run once:
}

void loop() 
{
  digitalWrite(lad1 , HIGH);
  delay(500);
  digitalWrite(lad1, LOW);
  delay(500);
  digitalWrite(lad2 , HIGH);
  delay(500);
  digitalWrite(lad2, LOW);
  delay(500);
  // put your main code here, to run repeatedly:
}