int pin_1 = 4;
int pin_2 = 5;
int pin_3 = 6;
int pin_4 = 7;
int pin_5 = 8;
int pin_6 = 9;
int pin_7 = 10;
int pin_8 = 11;


void setup() {
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(10, OUTPUT);
pinMode(11, OUTPUT);
}


void loop() {
 digitalWrite(pin_1, HIGH);
 digitalWrite(pin_2, HIGH);
 digitalWrite(pin_3, HIGH);
 digitalWrite(pin_4, HIGH);
 digitalWrite(pin_5, HIGH);
 digitalWrite(pin_6, HIGH);
 digitalWrite(pin_7, HIGH);
 digitalWrite(pin_8, HIGH);
 delay(2000);
 digitalWrite(pin_1, LOW);
 digitalWrite(pin_2, LOW);
 digitalWrite(pin_3, LOW);
 digitalWrite(pin_4, LOW);
 digitalWrite(pin_5, LOW);
 digitalWrite(pin_6, LOW);
 digitalWrite(pin_7, LOW);
 digitalWrite(pin_8, LOW);
 delay(2000);
}