int pinLed[] ={2,3,4,5,6,7,8,9};
int i,j;
void chaytraiphai()
{
  static int chay1 = 0;
  for (i=0;i<8;i++)
  digitalWrite(pinLed[i],LOW);
  digitalWrite(pinLed[chay1],HIGH);
  delay(300);
  chay1++;
  if (chay1>8)
  chay1 = 0;
}
  void setup()
  {
    for(i=0; i<=7;i++)
    pinMode(pinLed[i], OUTPUT);
  }
  void loop()
  {
    chaytraiphai();
  }