const int pinLED1 = 4;
const int pinLED2 = 5;
const int pinLED3 = 6;
const int pinLED4 = 7;

void setup() 
{
  pinMode (pinLED1, OUTPUT);
  pinMode (pinLED2, OUTPUT);
  pinMode (pinLED3, OUTPUT);
  pinMode (pinLED4, OUTPUT);
}
void loop()
{ 
  digitalWrite (pinLED1, HIGH);
  digitalWrite (pinLED4, HIGH);
  delay(1000);
  digitalWrite (pinLED2, HIGH);
  digitalWrite (pinLED3, HIGH);
  delay(1000);
  digitalWrite (pinLED1, LOW);
  digitalWrite (pinLED2, LOW);
  digitalWrite (pinLED3, LOW);
  digitalWrite (pinLED4, LOW);
  delay(1000);
}
  void loop()
{
  digitalWrite (pinLED1, HIGH);
  delay(1000);
  digitalWrite (pinLED2, HIGH);
  delay(1000);
  digitalWrite (pinLED3, HIGH);
  delay(1000);
  digitalWrite (pinLED4, HIGH);
  delay(1000);
  digitalWrite (pinLED4, LOW);
  delay(1000);
  digitalWrite (pinLED3, LOW);
  delay(1000);
  digitalWrite (pinLED2, LOW);
  delay(1000);
  digitalWrite (pinLED1, LOW);
  delay(1000);
}
 void loop()
{
  digitalWrite (pinLED4, HIGH);
  delay(1000);
  digitalWrite (pinLED3, HIGH);
  delay(1000);
  digitalWrite (pinLED2, HIGH);
  delay(1000);
  digitalWrite (pinLED1, HIGH);
  delay(1000);
  digitalWrite (pinLed1, LOW);
  delay(1000);
  digitalWrite (pinLED2, LOW);
  delay(1000);
  digitalWrite (pinLED3, LOW);
  delay(1000);
  digitalWrite (pinLED4, LOW);
  delay(1000);
}