#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 20, 4);

void setup()
{
	// initialize the LCD
	lcd.begin();

	// Turn on the blacklight and print a message.
  char b[4][20] = {{"Hallo               "},{"Arduino            A"},{"Liquid             B"},{"Crystal             "}};
  print(b);
 delay(1000);
}

void loop()
{

}

void print(char a[4][20]) {
  //cange row 2 & 3
  for(int i = 0; i < 20; i++) {
    int j = a[1][i];
    a[1][i] = a[2][i];
    a[2][i] = j;
  }
  
  lcd.clear();
  lcd.blink();
  lcd.setCursor(0,0);
  delay(2000);
  lcd.print(a[0]);
  lcd.noBlink();
}