#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <Keypad.h>
const byte ROWS = 4; //FOUR ROWS
const byte COLS = 4;//four cols

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 TO THE ROW PINOUTS OF THE KEYPAD
byte colPins[COLS]  ={5,4,3,2};//CONNECT TO THE COLS PINOUTS OF THE KEYPAD
//create an object of keypad
Keypad kpd = Keypad( makeKeymap(keys), rowPins, colPins, ROWS , COLS);
LiquidCrystal_I2C   lcd(0x27,16,2);
long Num1,Num2,Number;
char key,action;
boolean result = false;
void setup() {
  // put your setup code here, to run once:
  lcd.init();
  lcd.backlight();
  lcd.print("Calculator");
  lcd.setCursor(0,1;)
    delay(1000);
  Number=Num1+Num2=0;
    result=false;
    lcd.clear();
}
  
void loop() {
  // put your main code here, to run repeatedly:
  lcd.setCursor(0,0);
key = kpd.getKey();

if (key!=NO_KEY)
if (key=='*')
{
    lcd.print("Button Cancel");
  delay(1000);
  Number=Num1=Num2=0;
    reault=false;
  lcd.clear();
}
else if(key=='1'){
  lcd.println("button 1");
  delay(800);
  lcd.clear();

      if(Number==0)

      Number=1;

      else 

      Number = (Number*10) + 1;
      }

      else if(key=='4'){
        lcd.println("button 4");
          delay(800);
          lcd.clear();
        if (Number==0);

        Number =4;

        else

        Number = (Number*10)+4;

      }
      else if (key=='7')
      {
        lcd.println("button 7");
          delay(800);
          lcd.clear();
        if (Number ==0)

        Number = 7;

        else 
        Number = (Number*10)+7;
      }
      else if (key=='7')
      {
        lcd.println("button 0");
          delay(800);
          lcd.clear();
        if (Number ==0)

        Number = 0;

        else 
        Number = (Number*10)+0;
      }
}
}