int pir_pin_1 = 2;
int pir_pin_2 = 3;
int pir_pin_3 = 4;
int pir_pin_20 = 5;

int led_1 = 8;
int led_2 = 9;
int led_3 = 10;
int led_20 = 11;


void setup() {
  pinMode(pir_pin_1, INPUT);
  pinMode(pir_pin_2, INPUT);
  pinMode(pir_pin_3, INPUT);
  pinMode(pir_pin_20, INPUT);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_20, OUTPUT);
}

void loop() {
  int worker_1 = digitalRead(pir_pin_1);
  int worker_2 = digitalRead(pir_pin_2);
  int worker_3 = digitalRead(pir_pin_3);
  int worker_20 = digitalRead(pir_pin_20);

  if(worker_1==HIGH)
  {
    digitalWrite(led_1, HIGH);
  }
  else
  {
    digitalWrite(led_1, LOW);
  }
  if(worker_2==HIGH)
  {
    digitalWrite(led_2, HIGH);
  }
  else
  {
    digitalWrite(led_2, LOW);
  }
  if(worker_3==HIGH)
  {
    digitalWrite(led_3, HIGH);
  }
  else
  {
    digitalWrite(led_3, LOW);
  }
  if(worker_20==HIGH)
  {
    digitalWrite(led_20, HIGH);
  }
  else
  {
    digitalWrite(led_20, LOW);
  }
  delay(500);

}