Adding value in variable of imported contract

Smart Contracts
1

Below is a simple contract which I wrote

//SPDX-License-Identifier: MIT
pragma solidity 0.8.17 ;  

contract Num
{
    uint256  public  nuu ;   

}

Below is another contract which I wrote

//SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import "./Num.sol";

contract Put
{
    Num[] public deploy ;
 
    function putfac() public               // creating and adding new instances of contract into array 
    {   Num dd = new Num() ; 
        deploy.push(dd);
    }

    function putvalue(uint256 serial , uint256 numput)  public  
    {
        Num ss = Num(deploy[serial]);
        ss.nuu = numput ;                                // trying to put value into variable of another contract
    }   
}

In 2nd contract , I imported the contract Num , and then I created an array of that contract type , created instance and now in function putvalue I am trying to add value in variable, however I am getting these errors:-

Capture
Capture998×533 28.5 KB

Can anyone tell me , why these errors are showing , how to remove them and how to add value in variable nuu from 2nd contract ?

2

The problem is this code:

Num ss = Num(deploy[serial]);

Not sure what you are trying to do there.
You could use:
deploy[0].nuu = numput Or deploy[serial].nuu

Both assume that you already created the instance