const int led1= 5;
const int led2= 6;

void setup() {
  // put your setup code here, to run once:
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  delay(700);

  digitalWrite(led1,LOW);
  digitalWrite(led2,HIGH);
  delay(700);
}