const int led1 = 11;
const int led2 = 12;
const int led3 = 13;
const int led4 = 10;
const int led5 = 9;
const int led6 = 8;
const int led7 = 7;


void setup() {
  
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(led5, OUTPUT);
  pinMode(led6, OUTPUT);
  pinMode(led7, OUTPUT);
}

void loop() {
  
  digitalWrite(led1, HIGH);
  delay(100);
  digitalWrite(led1, LOW); 
  delay(100);

  digitalWrite(led2, HIGH); 
  delay(100);
  digitalWrite(led2, LOW); 
  delay(100);

  digitalWrite(led3, HIGH); 
  delay(100);
  digitalWrite(led3, LOW);   
  delay(100);
 
 digitalWrite(led4, HIGH);
  delay(100);
  digitalWrite(led4, LOW);
  delay(100);

  digitalWrite(led5, HIGH);
  delay(100);
digitalWrite(led5, LOW);
delay(100);
digitalWrite(led6, HIGH);
delay(100);
digitalWrite(led6, LOW);
delay(100);

digitalWrite(led7, HIGH); 
delay(100);
digitalWrite(led7, LOW);   
delay(100);
}