#include <LiquidCrystal.h>
LiquidCrystal lcd(13,12,7,6,5,4);

void setup() 
{
  lcd.begin(20, 4);
  Serial.begin(9600);
  Serial.print("Zadaj meno: ");
}

void loop() 
{
  if(Serial.available())
  {
    String meno = Serial.readStringUntil('\n');
    lcd.print("Ahoj " + String(meno));
  }

}