#include <LiquidCrystal.h>
LiquidCrystal lcd(13,12,11,10,9,8);

String pole[] = {"Pondelok", "Utorok", "Streda", "Stvrtok", "Piatok", "Sobota", "Nedela"};
int x = 0;

void setup() 
{
  lcd.begin(16,2);

  SREG |= 1<<7;
  DDRD &= ~(1<<2);
  PORTD |= 1<<2;

  DDRD &= ~(1<<3);
  PORTD |= 1<<3;

  PCICR |= 1<<PCIE2;

  PCMSK2 |= 1<<PCINT18;
  PCMSK2 |= 1<<PCINT19;

  lcd.print(pole[0]);
}

void loop() 
{
  

}

ISR(PCINT2_vect)
{
  if((PIND & (1<<3)) == 0)
  {
    lcd.clear();
    x++;
    if(x > 6)
    x = 0;

    lcd.print(pole[x]);
    
  }
  if((PIND & (1<<2)) == 0)
  {
    lcd.clear();
    x--;
    if(x < 0)
    x = 6;

    lcd.print(pole[x]);
  }
}