int i;
void setup() {
  // put your setup code here, to run once:
pinMode (3,OUTPUT);
pinMode (5,OUTPUT);
pinMode (6,OUTPUT);
pinMode (7,OUTPUT);
pinMode (8,OUTPUT);
pinMode (9, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
i = 0;
while (i <=9) {
  digitalWrite(i , HIGH);
  delay (500);
  digitalWrite(i , LOW);
  delay (500);
  i ++;
}
  return 0;
}