int buz=7;
void setup() {
  // put your setup code here, to run once:
for(int i=1; i<5; i++){
  pinMode(i, OUTPUT);
}
pinMode(buz, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
for( int i=4; i>0; i--){
  if(i%2==0){
    digitalWrite(i, HIGH);
  }else{
    digitalWrite(i, LOW);
  }
}

tone(buz,270);//noTone(buz); #for off or no sound
delay(3000);//milisecond

for( int i=4; i>0; i--){
  if(i%2!=0){
    digitalWrite(i, HIGH);
  }else{
    digitalWrite(i, LOW);
  }
}
tone(buz,670);//noTone(buz); #for off or no sound
delay(3000);//milisecond
}