int btn[]={2,3,4,5};
int LEDS[]={9,10,12,13};


void setup() {
  for(int i=0; i<4;i++)
  {
    pinMode(LEDS[i], OUTPUT);
    pinMode(btn[i], INPUT_PULLUP);
  }

}

void loop() {
if (digitalRead(btn[0])==LOW)
{
  digitalWrite(LEDS[0], HIGH);
  digitalWrite(LEDS[1], HIGH);
  digitalWrite(LEDS[2], HIGH);
  digitalWrite(LEDS[3], HIGH);
}
else if (digitalRead(btn[0])==HIGH)
{
  digitalWrite(LEDS[0], LOW);
  digitalWrite(LEDS[1], LOW);
  digitalWrite(LEDS[2], LOW);
  digitalWrite(LEDS[3], LOW);
}

if (digitalRead(btn[1])==LOW)
{
  digitalWrite(LEDS[0], HIGH);delay(300);
  digitalWrite(LEDS[1], HIGH);delay(300);
  digitalWrite(LEDS[2], HIGH);delay(300);
  digitalWrite(LEDS[3], HIGH);delay(300);
}
else if (digitalRead(btn[1])==HIGH)
{
  digitalWrite(LEDS[0], LOW);
  digitalWrite(LEDS[1], LOW);
  digitalWrite(LEDS[2], LOW);
  digitalWrite(LEDS[3], LOW);
}

if (digitalRead(btn[2])==LOW)
{
  digitalWrite(LEDS[3], HIGH);delay(400);
  digitalWrite(LEDS[2], HIGH);delay(400);
  digitalWrite(LEDS[1], HIGH);delay(400);
  digitalWrite(LEDS[0], HIGH);delay(400);
}
else if (digitalRead(btn[2])==HIGH)
{
  digitalWrite(LEDS[0], LOW);
  digitalWrite(LEDS[1], LOW);
  digitalWrite(LEDS[2], LOW);
  digitalWrite(LEDS[3], LOW);
}


if (digitalRead(btn[3])==LOW)
{
  digitalWrite(LEDS[0], HIGH);
  digitalWrite(LEDS[1], HIGH);
  digitalWrite(LEDS[2], HIGH);
  digitalWrite(LEDS[3], HIGH);

  delay(2000);
}
else if (digitalRead(btn[3])==HIGH)
{
  digitalWrite(LEDS[0], LOW);
  digitalWrite(LEDS[1], LOW);
  digitalWrite(LEDS[2], LOW);
  digitalWrite(LEDS[3], LOW);
}




}