void setup() {
 pinMode(13, OUTPUT); 
 pinMode(4, OUTPUT); // put your setup code here, to run once:
}

void loop() {
 digitalWrite(13, HIGH); 
 delay(1000);
 digitalWrite(4, HIGH);
 delay(1000);
 digitalWrite(13, LOW);
 delay(1000);
 digitalWrite(4, LOW);
 delay(1000);// put your main code here, to run repeatedly:

}