void setup() {
pinMode(10, OUTPUT);
pinMode(8, OUTPUT);
pinMode(7, OUTPUT);
}

void loop() {
digitalWrite(10,HIGH);
delay(1000);
digitalWrite(10,LOW);
delay(1000);

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

digitalWrite(7,HIGH);
delay(1000);
digitalWrite(7,LOW);
delay(1000);
}