int LED13 = 13;
int LED12 = 12;
int LED11 = 11;
int LED10 = 10;
int LED9 = 9;
int LED8 = 8;
int LED7 = 7;
int LED6 = 6;
int LED5 = 5;
int LED4 = 4;
int LED3 = 3;
int LED2 = 2;

void setup() {
   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);
   pinMode(LED11, OUTPUT);
   pinMode(LED12, OUTPUT);
   pinMode(LED13, OUTPUT);
}


void loop() {                 
  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);
  digitalWrite(LED8, HIGH);     
  delay(100); 
  digitalWrite(LED8, LOW);     
  delay(100);
  digitalWrite(LED9, HIGH);    
  delay(100);  
  digitalWrite(LED9, LOW);    
  delay(100);
  digitalWrite(LED10, HIGH);    
  delay(100); 
  digitalWrite(LED10, LOW);    
  delay(100);
  digitalWrite(LED11, HIGH);    
  delay(100);  
  digitalWrite(LED11, LOW);    
  delay(100);
  digitalWrite(LED12, HIGH);    
  delay(100); 
  digitalWrite(LED12, LOW);    
  delay(100);
  digitalWrite(LED13, HIGH);     
  delay(100);  
  digitalWrite(LED13, LOW);    
  delay(100);
}