int timer = 100;
int thisPin;

int numPins;

void setup() {
  Serial.begin(9600);
  Serial.println("How many LEDs do you want to use?");
  Serial.println("Maximim is 11 pins");
  while (numPins == 0){
    numPins = Serial.parseInt();
  }
  Serial.print("You have selected ");
  Serial.print(numPins);
  Serial.println(" pins");

  thisPin = 2;
  while (thisPin <= numPins + 1)    
  {
    pinMode (thisPin, OUTPUT);
    thisPin++;      
  } 
} 

void loop() {
  thisPin = numPins + 1;
  while (thisPin > 1)    
  { 
    digitalWrite (thisPin, HIGH);   
    delay (timer);                  
    digitalWrite (thisPin, LOW);
    thisPin--;    
  }

  thisPin = 2;
  while (thisPin < numPins + 1) 
  { 
    digitalWrite (thisPin, HIGH);
    delay (timer);
    digitalWrite (thisPin, LOW);
    thisPin++;
  } 
} // End of Program