#include <LiquidCrystal_I2C.h> 
LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  lcd.init();
  lcd.backlight();
}
void loop() {
  lcd.setCursor(1,0);
  lcd.print("bai tap giua ki");
  delay(1000);
  lcd.clear();
  lcd.setCursor(1,1);
  lcd.print("hello");
  delay(1000);
  lcd.clear();
  lcd.setCursor(1,2);
  lcd.print("");
  delay(1000);
  lcd.clear();
}