For all unused pins, make them inputs with the internal pullup resistors enabled, e.g.
pinMode(5, INPUT_PULLUP);
pinMode(6, INPUT_PULLUP);
pinMode(7, INPUT_PULLUP);
For all unused pins, make them inputs with the internal pullup resistors enabled, e.g.
pinMode(5, INPUT_PULLUP);
pinMode(6, INPUT_PULLUP);
pinMode(7, INPUT_PULLUP);