#include <LiquidCrystal_I2C.h>

const int buttonPin1 = 2;    
const int buttonPin2 = 3;
const int buttonPin3 = 4;
const int buttonPin4 = 5;    

const int ledPin1=  6;   
const int ledPin2=  7;   
const int ledPin3=  8;   
const int ledPin4=  9;   

int buttonState1 = 0;         
int buttonState2 = 0;
int buttonState3 = 0;
int buttonState4 = 0;

LiquidCrystal_I2C lcd(0x27, 16, 2);


void setup() {
lcd.begin();
  lcd.backlight();
  pinMode(buttonPin1, INPUT);
  pinMode(buttonPin2, INPUT);
  pinMode(buttonPin3, INPUT);
  pinMode(buttonPin4, INPUT);

  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(ledPin4, OUTPUT);
  lcd.clear();
   lcd.print("Hello......");
   delay(2000);
}

void loop() {

  buttonState1 = digitalRead(buttonPin1);
   buttonState2 = digitalRead(buttonPin2);
   buttonState3 = digitalRead(buttonPin3);
   buttonState4 = digitalRead(buttonPin4);

  if (buttonState1 == LOW) 
  {
     digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
  } 
  else
  {
  if (buttonState2 == LOW) 
  {
     digitalWrite(ledPin2, HIGH);
     digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
  } 
  else
  {
if (buttonState3 == LOW) 
  {
     digitalWrite(ledPin3, HIGH);
     digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin4, LOW);
  } 
  else{
  if (buttonState4 == LOW) 
  {
     digitalWrite(ledPin4, HIGH);
     digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
  } 
  else{
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
  }
  }
  }
  }
delay(500);
}