int led1=13;
int led2=12;
int led3=11;
int led4=10;
int led5=9;
int led6=8;
int led7=7;
int led8=6;
int led9=5;
int led10=4;

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() {

for (int cont=0;cont<=10;cont++){
digitalWrite(led1, HIGH);
delay(400);
digitalWrite(led2, HIGH);
delay(400);
digitalWrite(led3, HIGH);
delay(400);
digitalWrite(led4, HIGH);
delay(400);
digitalWrite(led5, HIGH);
delay(400);
digitalWrite(led6, HIGH);
delay(400);
digitalWrite(led7, HIGH);
delay(400);
digitalWrite(led8, HIGH);
delay(400);
digitalWrite(led9, HIGH);
delay(400);
digitalWrite(led10, HIGH);
delay(400);
break;
}

for (int cont=10;cont>=0;cont--){
  digitalWrite(led10, LOW);
  delay(400);
  digitalWrite(led9, LOW);
  delay(400);
  digitalWrite(led8, LOW);
  delay(400);
  digitalWrite(led7, LOW);
  delay(400);
  digitalWrite(led6, LOW);
  delay(400);
  digitalWrite(led5, LOW);
  delay(400);
  digitalWrite(led4, LOW);
  delay(400);
  digitalWrite(led3, LOW);
  delay(400);
  digitalWrite(led2, LOW);
  delay(400);
  digitalWrite(led1, LOW);
  delay(400);
  break;


}

  

}