byte pinOnArr[4] = {9, 7, 5, 3};
byte pinOffArr[4] = {8, 6, 4, 2};
const byte relayPin = 13;

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

void loop()
{
  for (int i = 0; i < 4; i++) {
    if (!digitalRead(pinOnArr[i]))
    {
      while (digitalRead(pinOffArr[i]))
      {
        digitalWrite(relayPin, true);
      }
      digitalWrite(relayPin, false);
    }
  }
  delay(50);
}