void setup() {

  DDRD = &= !B00100000;  //Set only D5 as INPUT

}



void loop() {

  //This is NOT equal to: int value = digitalRead(5);

  //Why? Because value = an 8 bit value. For only 1 bit, you need to shif regisers

  int value = PIND & B00100000;     

 



  //This is equal to  int value2 = digitalRead(5);

  //Since we read the fifth bit, we need to shift 5 times to the right

  int value2 = (PIND >> 5 & B00100000 >> 5);



  //In case you want to make an if decision you don't have to shift

  //Next line equal to: if(digitalRead(5))

  if(PIND & B00100000){

    //Add your code...

  }



  //We can invert the result: Next line equal to: if(!digitalRead(5))

  if!(PIND & B00100000){

    //Add your code...

  }

}