int red = 13;
int green = 12;
int buttonState = 0;

#include <Keypad.h>

#include <LiquidCrystal_I2C.h>

#define LCD_ADDR 0x27
#define LCD_COLUMNS 16
#define LCD_ROWS 2

LiquidCrystal_I2C lcd(LCD_ADDR, LCD_COLUMNS, LCD_ROWS);

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

uint8_t colPins[COLS] = { 5, 4, 3, 2 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
String password="";
String secretpassword="1234";

void setup() {
     pinMode(red, OUTPUT);
   pinMode(green, OUTPUT);
  Serial.begin(9600);
    lcd.begin(16,2);

  lcd.init();
  lcd.backlight();
}

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

  if (key != NO_KEY){

 if (password == secretpassword)
     {
      digitalWrite(green , HIGH);
      digitalWrite(red, LOW);
     }


    else
    {
      digitalWrite(red, HIGH);
      digitalWrite(green,LOW);
    }

    if (key == '#')
    {lcd.init();
       if (password == secretpassword)
         {lcd.setCursor(0,1);
         lcd.print("Congratulation");
         password = "";
          }
       else
       {
    lcd.setCursor(0,1);
    lcd.print("try again");
    password = "";
       }
    }
    else{
      lcd.setCursor(5,0);
      password=password+key;
    }



       
     Serial.println(password);
    
  }
  }