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

const byte ROWS = 4; // Number of keypad rows
const byte COLS = 4; // Number of keypad columns

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

byte rowPins[ROWS] = {9, 8, 7, 6};    // Connect keypad ROW0, ROW1, ROW2, ROW3 to these Arduino pins
byte colPins[COLS] = {5, 4, 3, 2};    // Connect keypad COL0, COL1, COL2, COL3 to these Arduino pins

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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16 column and 2 rows

String text ; // Stores the inputted number

void setup() {
  lcd.begin(16, 2);
  lcd.backlight();
  lcd.print("Enter Number:");
}

void loop() {
  char key = keypad.getKey(); // Read the pressed key

  if (key) {
    if (key == '#') {
      if (text.length() > 0) {
        text.remove(text.length() - 1); // Remove the last character
        lcd.setCursor(0, 1); // Set the cursor position on the LCD
        lcd.print("        "); // Clear the previous text
        lcd.setCursor(0, 1); // Set the cursor position again
        lcd.print(text); // Display the updated text
      }
    } else {
      text += key; // Append the pressed key to the text
      lcd.setCursor(0, 1); // Set the cursor position on the LCD
      lcd.print(text); // Display the updated text
    }
  }
}
// Make sure to include the necessary libraries (Keypad and LiquidCrystal_I2C) before uploading the code to your microcontroller. Adjust the pin assignments and I2C address for your specific setup if needed.