void setup() {
  pinMode(8,1);
  pinMode(7,1);
  Serial.begin(9600);
}

void loop() {
  if(random(0,2)){
      digitalWrite(8,1);
      delay(200);
      digitalWrite(8,0);

  }else{
      digitalWrite(7,1);
      delay(200);
      digitalWrite(7,0);
  }
  delay(100);

}