You can try something like this (cf Starkgate code):

```
 uint256 constant UINT256_PART_SIZE_BITS = 128;
 uint256 constant UINT256_PART_SIZE = 2**UINT256_PART_SIZE_BITS;
```

And payload will be like this :

```
uint256[] memory payload = new uint256[](3);
payload[0] = l2Recipient;
payload[1] = amount & (UINT256_PART_SIZE - 1);
payload[2] = amount >> UINT256_PART_SIZE_BITS;
```

Then on L2 you will received amount as 2 felt, high and low. Then you juste have to use it with ` let (amount: Uint256) =Uint256(low=low, high=high)`  And that's it.





How can I send a Uint256 amount of ERC20 tokens from L1 to starknet?
I have "amount" as a uint256 on L1 but how should I build my payload for "`sendMessageToL2`" to match the Uint256 format of Cairo?

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Newton

How can I send a Uint256 amount of ERC20 tokens from L1 to starknet? And how should I build my payload for "sendMessageToL2" to match the Uint256 format of Cairo?

What’s the difference between Account Abstraction (AA) and Externally Owned Accounts (EOA)?

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What’s the difference between Account Abstraction (AA) and Externally Owned Accounts (EOA)?

How can I find the current contract's address in Cairo? Is there an equivalent to `address(this)` from Solidity?


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/575)_

Cairo: How do I find the current contract's address?

Hello! This is Day 2 of the 17 days of the Cairo challenge. And I have no idea how to solve the [playground](https://www.cairo-lang.org/playground/) exercise “Functions”. Perhaps you can help me?

```python
// The following code is missing the function `add1`.
// 1. Click on "Run" to see the error.
// 2. Write the function `add1`, based on `add1_square`, so
//    that the program terminates successfully.
//
// Note that `add1` doesn't have to call other functions.
//
// You can learn more about functions [here](https://www.cairo-lang.org/docs/how_cairo_works/functions.html).

// Write your code here.

func add1_square(x: felt) -> (x: felt) {
    // Call `add1` and unpack the result into `z`.
    let (z) = add1(y=x);
    return (x=z * z);
}

func main() {
    // Call `add1_square` and save the result into `res`.
    let (res) = add1_square(x=12);

    // Verify the computation.
    assert res = (12 + 1) * (12 + 1);
    return ();
}
```

---
> Answers to this question are a part of the ✨ **17 days of Cairo Lang with Playground & Newton.** ✨ 

*Vote for your favorite answer - the best answer will win a $10 award. A new day – a new reward! During the next 17 days, our goal is to attract more developers to the Cairo language and to systematize the knowledge of Cairo lang. [Read rules](https://www.notion.so/17-days-of-Cairo-Lang-with-Newton-550dfcda6a2d449ca468be293c776578)*

How to write a function in Cairo Lang (StarkNet)?

1. Can anyone explain how to get Goerli ETH tokens?

2. Also want to know how to bridge tokens from the Goerli ETH testnet and move them to Goerli2 (StarkNet)?


---

> thank's for your answers, summing up how to transfer funds and how to use Faucet on Ethereum:


1. For receiving ETH on Goerli Test Net, I used [Goerli PoW Faucet](https://goerli-faucet.pk910.de/).
As an alternative, [https://goerlifaucet.com/](https://goerlifaucet.com/) can be used, but it is required to authorize.

2. I installed ArgentX using the links below and transferred funds using the [HashStack service for StarkNet](https://goerli2-bridge.hashstack.finance)

![https://www.bbntimes.com/images/Ethereum_Faucet.jpeg](https://www.bbntimes.com/images/Ethereum_Faucet.jpeg)

StarkNet Faucet: How can I get a Goerli-2 eth faucet tokens (StarkNet)?

Any nft marketplace has launched on starknet L2?

_This question was originally posted on [StarkNet Discord](https://www.newton.so/view?tags=discord)_

Any NFT marketplace has launched on starknet L2?

Hey, I'm using StartkNet.py to make a transaction and it gets rejected. 
How to solve it?

What does this error means? (AssertionError: assert_not_zero failed: 0 = 0.)

What is the maximum value a `uint` can store?

I need to understand a couple of things:

1. What is the maximum value `a felt` and `uint` can store?
2. Are the maximum values stored in felt and uint the same?

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How can I send a Uint256 amount of ERC20 tokens from L1 to starknet? And how should I build my payload for "sendMessageToL2" to match the Uint256 format of Cairo?

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