int leds[] = {5, 6, 7};
int Speed = 2, Reverse = 3;

void setup() 
{
  pinMode(leds[0], OUTPUT); // Set on-board LED as output
  pinMode(leds[1], OUTPUT);
  pinMode(leds[2], OUTPUT);
  pinMode(Speed, INPUT_PULLUP);
  pinMode(Reverse, INPUT_PULLUP);
}

void loop()
{
  int delayTime;
  if (digitalRead(Speed) == LOW)
  {
    delayTime = 150;
  } else {
    delayTime = 300;
  }

  if (digitalRead(Reverse) == LOW) 
  {
    for (int i = 2; i >= 0; i--)
    {
      digitalWrite(leds[i], HIGH);
      delay(delayTime);
      digitalWrite(leds[i], LOW);
      delay(delayTime);
    }
  } else {
    for (int i = 0; i < 3; i++)
    {
      digitalWrite(leds[i], HIGH);
      delay(delayTime);
      digitalWrite(leds[i], LOW);
      delay(delayTime);
    }
  }
}