#define LED2 19
#define LED3 18
#define LED4 5
void setup() { 
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
}

void loop() {
for(int i = 0; i < 2; i++)
{
  digitalWrite(LED2, LOW);
  delay(1000);
  digitalWrite(LED2, HIGH);
  delay(1000);
}
for(int i = 0; i < 3; i++)
{
  digitalWrite(LED3, LOW);
  delay(1000);
  digitalWrite(LED3, HIGH);
  delay(1000);
}
for(int i = 0; i< 4 ; i++)
{
  digitalWrite(LED4, LOW);
  delay(1000);
  digitalWrite(LED4, HIGH);
  delay(1000);
}
for(int i = 0; i < 3; i++)
{
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  delay(1000);
  digitalWrite(LED2, HIGH);
  digitalWrite(LED3, HIGH);
  digitalWrite(LED4, HIGH);
  delay(1000);
  delay(500);
}
}