const int ledPin =  2;

unsigned long previousMillis = 0;
unsigned long interval = 500;
int x = 1 ;
void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(115200);
  Serial.println("Input:");
  Serial.setTimeout(2); // timeout for parseInt
}

void loop()
{

  if (Serial.available())
  {
    int steps = Serial.parseInt();
    while ( x < steps)
    {

      if (millis() - previousMillis > interval)
      {
        previousMillis = millis();
        if (digitalRead(ledPin) == LOW )
        {
          digitalWrite(ledPin, HIGH);
          x++;
        }
        else {
          digitalWrite(ledPin, LOW);
          x++;
        }
      }

    }
  }
  x = 0 ;

}