const int relayPin = 10; // Connect the IN pin of the relay module to D9
const int switchPins[] = {2, 3, 4, 5, 6, 7, 8, 9}; // Connect switches to digital pins D2 to D9
const int numSwitches = sizeof(switchPins) / sizeof(switchPins[0]);

int numSwitchesToActivate = 4; // Set the number of switches you want to activate

bool relayNormallyOpen = true; // Set to true for NO relay, false for NC relay

unsigned long relayOnTime = 5000; // 5 seconds

void setup() {
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, relayNormallyOpen ? LOW : HIGH);

  for (int i = 0; i < numSwitches; i++) {
    pinMode(switchPins[i], INPUT_PULLUP);
  }
}

void loop() {
  int numActivatedSwitches = 0;

  for (int i = 0; i < numSwitches; i++) {
    if (digitalRead(switchPins[i]) == LOW) {
      numActivatedSwitches++;
    }
  }

  if (numActivatedSwitches == numSwitchesToActivate) {
    activateRelay();
  }
}

void activateRelay() {
  digitalWrite(relayPin, relayNormallyOpen ? HIGH : LOW);
  delay(relayOnTime);
  digitalWrite(relayPin, relayNormallyOpen ? LOW : HIGH);
}