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

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(1, 0);
  lcd.print("HELLO PROF");
  pinMode(3, INPUT_PULLUP);
  pinMode(4, OUTPUT);
}

void loop() {

  if (digitalRead(3) == LOW) 
  {
    lcd.setCursor(0, 1);
    lcd.print("LED EST ALLUMEE");
    digitalWrite(4, HIGH);


  }
  else
  { 
    lcd.setCursor(0, 1);
    lcd.print("LED EST ETEINTE");
    digitalWrite(4, LOW);
  }


}