int led1 = 21;
int led2 = 22;
int led3 = 23;

int pulsador = 19;
int val;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(pulsador, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  val = digitalRead(pulsador);
  if(val == HIGH){
    for(int i=0; i<3; i++){
      digitalWrite(led1, HIGH);
      delay(500);
      digitalWrite(led1, LOW);
      delay(500);
    }
    for(int i=0; i<3; i++){
      digitalWrite(led2, HIGH);
      delay(500);
      digitalWrite(led2, LOW);
      delay(500);
    }
    for(int i=0; i<3; i++){
      digitalWrite(led3, HIGH);
      delay(500);
      digitalWrite(led3, LOW);
      delay(500);
    }
  }
}