void setup() {
pinMode(13, OUTPUT);


}

void loop() {
digitalWrite(13, HIGH); 
delay (1000);
digitalWrite(13, LOW); 
delay (1000);

digitalWrite(12, HIGH); 
delay (1000);
digitalWrite(12, LOW); 
delay (1000);

digitalWrite(11, HIGH); 
delay (1000);
digitalWrite(11, LOW); 
delay (1000);

digitalWrite(10, HIGH); 
delay (1000);
digitalWrite(10, LOW); 
delay (1000);

digitalWrite(9, HIGH); 
delay (1000);
digitalWrite(9, LOW); 
delay (1000);

digitalWrite(8, HIGH); 
delay (1000);
digitalWrite(8, LOW); 
delay (1000);

}