int main(){
  DDRD |= (1<<5)|(1<<6)|(1<<7);
  DDRB &= ~((1<<0)|(1<<1)|(1<<2));
  PCICR |= (1<<0);//Pin change interrupt control register:(pin 7....0):
  PCMSK0 |= (1<<0)|(1<<1)|(1<<2);//Pin Change Mask Register:
  sei();

  while(1){
     //
  }
}
ISR(PCINT0_vect){
  if(PINB & (1<<0)){
    PORTD &= ~(1<<6);
    PORTD &= ~(1<<5);
    PORTD ^= (1<<7);
  }else if(PINB & (1<<1)){
    PORTD &= ~(1<<7);
    PORTD &= ~(1<<5);
    PORTD |= (1<<6);
  }else if(PINB & (1<<2)){
    PORTD &= ~(1<<7);
    PORTD &= ~(1<<6);
    PORTD |= (1<<5);
  }
}