int led1=13;
int led2=12;
int led3=11;
int led4=10;
void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);}


void loop(){ 
digitalWrite(led1,HIGH);
delay(500);
digitalWrite(led1,LOW);
//delay(1000);

digitalWrite(led2,HIGH);
delay(500);
digitalWrite(led2,LOW);
//delay(1000);

digitalWrite(led3,HIGH);
delay(500);
digitalWrite(led3,LOW);
//delay(1000);

digitalWrite(led4,HIGH);
delay(500);
digitalWrite(led4,LOW);
//delay(1000);3
////////////////////////////////////////////////////////////////

digitalWrite(led3,HIGH);
delay(500);
digitalWrite(led3,LOW);
//delay(1000);

digitalWrite(led2,HIGH);
delay(500);
digitalWrite(led2,LOW);
//delay(1000);


}