void setup() {
  pinMode(10, OUTPUT);
  pinMode(13, OUTPUT);
  pinMode(4, INPUT_PULLUP);
  pinMode(7, INPUT_PULLUP);
}

void loop() {
  bool sw4 = digitalRead(4);
  bool sw7 = digitalRead(7);
  if (sw7==0 && sw4==0 || sw7==1 && sw4==1) {
    digitalWrite(10, HIGH);
    digitalWrite(13, LOW);
    delay(250);
    digitalWrite(10, LOW);
    digitalWrite(13, HIGH);
    delay(250);
  }
  if (sw7==0 && sw4==1 || sw7==1 && sw4==0) {
    digitalWrite(10, HIGH);
    digitalWrite(13, HIGH);
    delay(250);
    digitalWrite(10, LOW);
    digitalWrite(13, LOW);
    delay(250);
  }
}