int led1= 11;
int led2= 10;
int led3= 9;
int led4= 8;
int led5= 7;
int led6= 6;
int led7= 5;
int led8= 4;
int led9= 3;
int led10= 2;

  void setup(){
    pinMode(led1, OUTPUT);
    pinMode(led2, OUTPUT);
    pinMode(led3, OUTPUT);
    pinMode(led4, OUTPUT);
    pinMode(led5, OUTPUT);
    pinMode(led6, OUTPUT);
    pinMode(led7, OUTPUT);
    pinMode(led8, OUTPUT);
    pinMode(led9, OUTPUT);
    pinMode(led10, OUTPUT);
  }
  void loop(){
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    delay(500);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
    delay(500);
    digitalWrite(led5, HIGH);
    digitalWrite(led6, HIGH);
    delay(500);
    digitalWrite(led7, HIGH);
    digitalWrite(led8, HIGH);
    delay(500);
    digitalWrite(led9, HIGH);
    digitalWrite(led10, HIGH);
    delay(500);

    digitalWrite(led10, LOW);
    delay(500);
    digitalWrite(led9, LOW);
    delay(500);
    digitalWrite(led8, LOW);
    delay(500);
    digitalWrite(led7, LOW);
    delay(500);
    digitalWrite(led6, LOW);
    delay(500);
    digitalWrite(led5, LOW);
    delay(500);
    digitalWrite(led4, LOW);
    delay(500);
    digitalWrite(led3, LOW);
    delay(500);
    digitalWrite(led2, LOW);
    delay(500);
    digitalWrite(led1, LOW);
    delay(500);

    digitalWrite(led1, HIGH);
    delay(500);
    digitalWrite(led2, HIGH);
    delay(500);
    digitalWrite(led3, HIGH);
    delay(500);
    digitalWrite(led4, HIGH);
    delay(500);
    digitalWrite(led5, HIGH);
    delay(500);
    digitalWrite(led6, HIGH);
    delay(500);
    digitalWrite(led7, HIGH);
    delay(500);
    digitalWrite(led8, HIGH);
    delay(500);
    digitalWrite(led9, HIGH);
    delay(500);
    digitalWrite(led10, HIGH);
    delay(500);

    digitalWrite(led1, LOW);
    digitalWrite(led10, LOW);
    delay(500);
    digitalWrite(led2, LOW);
    digitalWrite(led9, LOW);
    delay(500);
    digitalWrite(led3, LOW);
    digitalWrite(led8, LOW);
    delay(500);
    digitalWrite(led4, LOW);
    digitalWrite(led7, LOW);
    delay(500);
    digitalWrite(led5, LOW);
    digitalWrite(led6, LOW);
    delay(500);

  }