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

#define PASSWORD "1234"  // Correct password

LiquidCrystal_I2C lcd(0x27, 16, 2);

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte rowPins[ROWS] = {13, 12, 14, 27};
byte colPins[COLS] = {26, 25, 33, 32};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

String inputPassword = "";

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");
}

void loop() {
  char key = keypad.getKey();

  if (key) {
    if (key == '#') { // Submit button
      lcd.clear();
      if (inputPassword == PASSWORD) {
        lcd.print("correct password!");
      } else {
        lcd.print("Wrong Password!");
      }
      delay(2000);
      lcd.clear();
      lcd.print("Enter Password:");
      inputPassword = "";
    } else if (key == '*') { // Clear input
      inputPassword = "";
      lcd.setCursor(0, 1);
      lcd.print("                ");
    } else { // Collect input
      inputPassword += key;
      lcd.setCursor(0, 1);
      lcd.print(inputPassword);
    }
  }
}