Inherit

pragma solidity ^0.4.0;

contract grandfather{
    
    uint public gudong = 200;
    
    function zhongdi() returns(string){
        
        return "Heiyoyo...";
    }
}

contract father is grandfather{
    
    uint public money = 10000;
    
    function dahan() returns(string){
        
        return "Zzzzz.....";
        
    }

}

contract son is father{
    
    function getMoney() returns(uint){
        
        return money;
        
    }// son inherits variable money from father
    
    function maobing() returns(string){
        
        return dahan();
        
    }// son inherits function dahan() from father
    
    function getGudong() returns(uint){
        
        return gudong;
        
    }// gudong is inherited from father from grandfather, it is a case of successive inheritant
    
    function work() returns(string){
        
        return zhongdi();
        
    }// zhongdi() is inherited from father, from grandfather
    
}