// File: Context.sol



// SPDX-License-Identifier: MIT

/***************************************************************************
          ___        __         _     __           __   __ ___
        / __ \      / /_  _____(_)___/ /____       \ \ / /  _ \
       / / / /_  __/ __/ / ___/ / __  / __  )       \ / /| |
      / /_/ / /_/ / /_  (__  ) / /_/ / ____/         | | | |_
      \____/\____/\__/ /____/_/\__,_/\____/          |_|  \___/
                                       
****************************************************************************/

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: OSYC.sol



// SPDX-License-Identifier: MIT

/***************************************************************************
          ___        __         _     __           __   __ ___
        / __ \      / /_  _____(_)___/ /____       \ \ / /  _ \
       / / / /_  __/ __/ / ___/ / __  / __  )       \ / /| |
      / /_/ / /_/ / /_  (__  ) / /_/ / ____/         | | | |_
      \____/\____/\__/ /____/_/\__,_/\____/          |_|  \___/
                                       
****************************************************************************/

pragma solidity ^0.8.0;

import "./SafeMath.sol";
import "./Ownable.sol";

contract OSYC is Ownable {
    using SafeMath for uint256;

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    uint256 _totalSupply;
    uint256 public MAX_SUPPLY;

    mapping(address => bool) public managers;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );

    constructor() {
        _name = "Outside YC";
        _symbol = "$OSYC";
        _decimals = 18;

        MAX_SUPPLY = 4000000 ether;
    }

    function addManager(address _address) external onlyOwner {
        managers[_address] = true;
    }

    function removeManager(address _address) external onlyOwner {
        managers[_address] = false;
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);

        return true;
    }

    function allowance(address owner, address spender)
        public
        view
        returns (uint256)
    {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);

        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public returns (bool) {
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()].sub(amount)
        );
        _transfer(sender, recipient, amount);

        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0x0));
        require(recipient != address(0x0));

        _balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);

        emit Transfer(sender, recipient, amount);
    }

    function mint(address to, uint256 amount) public {
        require(
            managers[msg.sender] == true,
            "This address is not allowed to interact with the contract"
        );
        _mint(to, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0x0));
        require(
            MAX_SUPPLY >= _totalSupply.add(amount),
            "limited by Max Supply"
        );

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);

        emit Transfer(address(0x0), account, amount);
    }

    function burn(address from, uint256 amount) external {
        require(
            managers[msg.sender] == true,
            "This address is not allowed to interact with the contract"
        );
        _burn(from, amount);
    }

    function burn(uint256 amount) external {
        _burn(msg.sender, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0x0));

        _balances[account] = _balances[account].sub(amount);
        _totalSupply = _totalSupply.sub(amount);

        emit Transfer(account, address(0x0), amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0x0));
        require(spender != address(0x0));

        _allowances[owner][spender] = amount;

        emit Approval(owner, spender, amount);
    }
}

// File: Ownable.sol



// SPDX-License-Identifier: MIT

/***************************************************************************
          ___        __         _     __           __   __ ___
        / __ \      / /_  _____(_)___/ /____       \ \ / /  _ \
       / / / /_  __/ __/ / ___/ / __  / __  )       \ / /| |
      / /_/ / /_/ / /_  (__  ) / /_/ / ____/         | | | |_
      \____/\____/\__/ /____/_/\__,_/\____/          |_|  \___/
                                       
****************************************************************************/


pragma solidity ^0.8.0;

import "./Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: SafeMath.sol



// SPDX-License-Identifier: MIT

/***************************************************************************
          ___        __         _     __           __   __ ___
        / __ \      / /_  _____(_)___/ /____       \ \ / /  _ \
       / / / /_  __/ __/ / ___/ / __  / __  )       \ / /| |
      / /_/ / /_/ / /_  (__  ) / /_/ / ____/         | | | |_
      \____/\____/\__/ /____/_/\__,_/\____/          |_|  \___/
                                       
****************************************************************************/

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}