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contracts...inheritance.sol

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract A{
    uint private x= 100;
    uint public y =200;
    address private addr = msg.sender;

    function fun1() public pure returns(string memory){
        return " i am in contract A fun1";
    }
      function fun2() public pure returns(string memory){
        return " i am in contract A fun2";
    }
    //add the virutal keyword to edit this function in derived class
      function fun3() public pure virtual returns(string memory){
        return " i am in contract A fun3";
    }
      function fun4() public pure virtual returns(string memory){
        return " i am in contract A fun4";
    }
}

contract B is A{
    //add override keyword in derived function to use in derived contract   

    function fun3() public pure override returns(string memory){
        return " i am in contract B func3";
    }

    function fun4() public pure virtual override returns(string memory){
        return " i am in contract B func4";
    }
}

contract C is B{
    
    function fun4() public pure override returns(string memory){
        return " i am contract C fun4";
    }
}