int const ledka1 = 13;
int const ledka2 = 12;
int const ledka3 = 11;

void setup() {
  // put your setup code here, to run once:
  pinMode(ledka1, OUTPUT);
  pinMode(ledka2, OUTPUT);
  pinMode(ledka3, OUTPUT);
  
}

void loop() {
  // put your main code here, to run repeatedly:
  funkcia();
  
}
void funkcia() {
  for (int thisPin = 11; thisPin <= 13; thisPin++) { 
  digitalWrite(thisPin, HIGH);
  delay(500);
  }
  delay(100);
  for (int thisPin = 11; thisPin <= 13; thisPin++) { 
  digitalWrite(thisPin, LOW);
  delay(500);
  }
  delay(100);
}