#include <LiquidCrystal_I2C.h>


LiquidCrystal_I2C lcd(0x27,16,2);
int cislo = 0;
bool x = true;

void setup()
{
  lcd.init();
  lcd.backlight();
  
  DDRB &= ~(1<<0);
  PORTB |= (1<<0);
  
  lcd.setCursor(0,0);
  lcd.print(cislo);
}

void loop()
{
  if ( (PINB&(1<<0))==0 && x == true ){
    cislo ++;
    lcd.clear();
    lcd.setCursor(0,0);
  	lcd.print(cislo);
    x = false;
  }
if ( (PINB&(1<<0))!=0 && x == false )
x = true;

}