Password Based LED Control

#include <Keypad.h>
#include <LiquidCrystal.h>
const int ROW_NUM = 4; //four rows
const int COLUMN_NUM = 3; //three columns
#define r1 9
#define r2 10
#define r3 11
#define r4 12
int r1s = LOW;
int r2s = LOW;
int r3s = LOW;
int r4s = LOW;
const int rs =A0, en =A1, d4 = A2, d5 =A3, d6 =A4, d7 =A5;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};

byte pin_rows[ROW_NUM] = {8, 7, 6, 5}; //connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {4, 3, 2}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

const String password = "1234"; // change your password here
String input_password;
String b1="2345";
String b2="3456";
String b3="4567";
String b4="5678";
String change="0000";

void setup(){
  pinMode(r1,OUTPUT);
  pinMode(r2,OUTPUT);
  pinMode(r3,OUTPUT);
  pinMode(r4,OUTPUT);

 digitalWrite(r1,0);
 digitalWrite(r2,0);
 digitalWrite(r3,0);
 digitalWrite(r4,0);

 lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("Password Based Light Controll");
  delay(1000);
  lcd.setCursor(0, 0);
  lcd.print("Enter Password : ");
  delay(1000);
  lcd.clear();
  Serial.begin(9600);
  input_password.reserve(32); // maximum input characters is 33, change if needed
}

void loop(){
  char key = keypad.getKey();
  lcd.setCursor(0, 0);
  lcd.print(key);
 if (key){
    Serial.println(key);
     
      
    if(key == '*') {
      input_password =""; // clear input password
    } else if(key == '#') {
      if(input_password==b1) {
        r1s =~r1s;
        digitalWrite(r1,r1s);
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Bulb 1 :");
        Serial.println("Bulb 1 : ");
        if(r1s==0)
       { lcd.print("ON");
        Serial.println("ON");}
        else 
       { lcd.print("OFF");
        Serial.println("OFF");}
        }
      else if(input_password==b2)
      { r2s =~r2s;
        digitalWrite(r2,r2s);
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Bulb 2 :");
        Serial.println("Bulb 2:");
        if(r2s==0)
        {lcd.print("ON");
        Serial.println("ON");}
        else 
        {lcd.print("OFF");
        Serial.println("OFF");} }
      else if(input_password==b3)
      { r3s =~r3s;
        digitalWrite(r3,r3s);
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Bulb 3 :");
        Serial.println("Bulb 3:");
        if(r3s==0)
        {lcd.print("ON");
        Serial.println("ON");}
        else{
        lcd.print("ON");
        Serial.println("OFF");}}
      else if(input_password==b4)
      { r4s =~r4s;
        digitalWrite(r4,r4s);
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Bulb 4 :");
        Serial.println("Bulb 4:");
        if(r4s==0)
        { lcd.print("ON");
          Serial.println("ON");}
        else {lcd.print("OFF");
        Serial.println("OFF");}}
      else {
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Wrong Password,Try again");
        Serial.println("password is incorrect, try again");
      }

      input_password = ""; // clear input password
    } else { lcd.setCursor(0, 1);
        lcd.print(input_password);
      input_password += key; // append new character to input password string
    }
  }
  
}