contract BetCoin is Context, Ownable, Pausable, IERC20 {
  using SafeMath for uint256;

  mapping (address => uint256) private _balances;

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

  uint256 private _maxSupply;
  uint256 private _totalSupply;

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

  /**
   * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
   * a default value of 18.
   *
   * To select a different value for {decimals}, use {_setupDecimals}.
   *
   * All three of these values are immutable: they can only be set once during
   * construction.
   */
  constructor() {
    uint256 fractions = 10 ** uint256(18);
    _name = "BetCoin";
    _symbol = "BET";
    _decimals = 18;
    _maxSupply = 14000000000 * fractions;
    _mint(owner(), _maxSupply);
  }

  /**
   * @dev Returns the name of the token.
   */
  function name() public view returns (string memory) {
    return _name;
  }

  /**
   * @dev Returns the symbol of the token, usually a shorter version of the
   * name.
   */
  function symbol() public view returns (string memory) {
    return _symbol;
  }

  /**
   * @dev Returns the number of decimals used to get its user representation.
   * For example, if `decimals` equals `2`, a balance of `505` tokens should
   * be displayed to a user as `5,05` (`505 / 10 ** 2`).
   *
   * Tokens usually opt for a value of 18, imitating the relationship between
   * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
   * called.
   *
   * NOTE: This information is only used for _display_ purposes: it in
   * no way affects any of the arithmetic of the contract, including
   * {IERC20-balanceOf} and {IERC20-transfer}.
   */
  function decimals() public view returns (uint8) {
    return _decimals;
  }

  /**
   * @dev See {IERC20-totalSupply}.
   */
  function totalSupply() public view override returns (uint256) {
    return _totalSupply;
  }

  /**
   * @dev See {IERC20-balanceOf}.
   */
  function balanceOf(address account) public view override returns (uint256) {
    return _balances[account];
  }

  /**
   * @dev See {IERC20-transfer}.
   *
   * Requirements:
   *
   * - `recipient` cannot be the zero address.
   * - the caller must have a balance of at least `amount`.
   */
  function transfer(address recipient, uint256 amount) public override returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }

  /**
   * @dev See {IERC20-allowance}.
   */
  function allowance(address owner, address spender) public view override returns (uint256) {
    return _allowances[owner][spender];
  }

  /**
   * @dev See {IERC20-approve}.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function approve(address spender, uint256 amount) public override returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  /**
   * @dev See {IERC20-transferFrom}.
   *
   * Emits an {Approval} event indicating the updated allowance. This is not
   * required by the EIP. See the note at the beginning of {ERC20}.
   *
   * Requirements:
   *
   * - `sender` and `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   * - the caller must have allowance for ``sender``'s tokens of at least
   * `amount`.
   */
  function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "transfer amount exceeds allowance"));
    return true;
  }

  /**
   * @dev Atomically increases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
    return true;
  }

  /**
   * @dev Atomically decreases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   * - `spender` must have allowance for the caller of at least
   * `subtractedValue`.
   */
  function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "decreased allowance below zero"));
    return true;
  }

  /**
   * @dev Issues `amount` tokens to the designated `address`.
   *
   * Can only be called by the current owner.
   * See {ERC20-_mint}.
   */
  // function mint(address account, uint256 amount) public onlyOwner {
  //   _mint(account, amount);
  // }

  /**
   * @dev Destroys `amount` tokens from the caller.
   *
   * See {ERC20-_burn}.
   */
  function burn(uint256 amount) public {
    _burn(_msgSender(), amount);
  }

  /**
   * @dev Destroys `amount` tokens from `account`, deducting from the caller's
   * allowance.
   *
   * See {ERC20-_burn} and {ERC20-allowance}.
   *
   * Requirements:
   *
   * - the caller must have allowance for ``accounts``'s tokens of at least
   * `amount`.
   */
  function burnFrom(address account, uint256 amount) public {
    uint256 decreasedAllowance = allowance(account, _msgSender()).sub(amount, "burn amount exceeds allowance");

    _approve(account, _msgSender(), decreasedAllowance);
    _burn(account, amount);
  }

  /**
   * @dev Disable the {transfer}, {mint} and {burn} functions of contract.
   *
   * Can only be called by the current owner.
   * The contract must not be frozen.
   */
  function freeze() public onlyOwner {
    _freeze();
  }

  /**
   * @dev Enable the {transfer}, {mint} and {burn} functions of contract.
   *
   * Can only be called by the current owner.
   * The contract must be frozen.
   */
  function unfreeze() public onlyOwner {
    _unfreeze();
  }

  /**
   * @dev Moves tokens `amount` from `sender` to `recipient`.
   *
   * This is internal function is equivalent to {transfer}, and can be used to
   * e.g. implement automatic token fees, slashing mechanisms, etc.
   *
   * Emits a {Transfer} event.
   *
   * Requirements:
   *
   * - `sender` cannot be the zero address.
   * - `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   */
  function _transfer(address sender, address recipient, uint256 amount) internal {
    require(sender != address(0), "transfer from the zero address");
    require(recipient != address(0), "transfer to the zero address");

    _beforeTokenTransfer(sender, recipient, amount);

    _balances[sender] = _balances[sender].sub(amount, "transfer amount exceeds balance");
    _balances[recipient] = _balances[recipient].add(amount);
    emit Transfer(sender, recipient, amount);
  }

  /** @dev Creates `amount` tokens and assigns them to `account`, increasing
   * the total supply.
   *
   * Emits a {Transfer} event with `from` set to the zero address.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   */
  function _mint(address account, uint256 amount) internal {
    require(account != address(0), "mint to the zero address");
    require(_totalSupply + amount <= _maxSupply, "mint amount exceeds max supply");

    _beforeTokenTransfer(address(0), account, amount);

    _totalSupply = _totalSupply.add(amount);
    _balances[account] = _balances[account].add(amount);
    emit Transfer(address(0), account, amount);
  }

  /**
   * @dev Destroys `amount` tokens from `account`, reducing the
   * total supply.
   *
   * Emits a {Transfer} event with `to` set to the zero address.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   * - `account` must have at least `amount` tokens.
   */
  function _burn(address account, uint256 amount) internal {
    require(account != address(0), "burn from the zero address");

    _beforeTokenTransfer(account, address(0), amount);

    _balances[account] = _balances[account].sub(amount, "burn amount exceeds balance");
    _totalSupply = _totalSupply.sub(amount);
    emit Transfer(account, address(0), amount);
  }

  /**
   * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
   *
   * This internal function is equivalent to `approve`, and can be used to
   * e.g. set automatic allowances for certain subsystems, etc.
   *
   * Emits an {Approval} event.
   *
   * Requirements:
   *
   * - `owner` cannot be the zero address.
   * - `spender` cannot be the zero address.
   */
  function _approve(address owner, address spender, uint256 amount) internal {
    require(owner != address(0), "approve from the zero address");
    require(spender != address(0), "approve to the zero address");

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }

  /**
   * @dev Hook that is called before any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * will be to transferred to `to`.
   * - when `from` is zero, `amount` tokens will be minted for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(address from, address to, uint256 amount) internal {
    require(!frozen(), "token transfer while frozen");
  }

  function _afterTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal {}
}
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
function _transfer(address sender, address recipient, uint256 amount) internal {
  require(sender != address(0), "transfer from the zero address");
  require(recipient != address(0), "transfer to the zero address");

  _beforeTokenTransfer(sender, recipient, amount);

  _balances[sender] = _balances[sender].sub(amount, "transfer amount exceeds balance");
  _balances[recipient] = _balances[recipient].add(amount);
  emit Transfer(sender, recipient, amount);
}

/**
 * @dev Moves tokens `amount` from `sender` to `recipient`.
 *
 * This is internal function is equivalent to {transfer}, and can be used to
 * e.g. implement automatic token fees, slashing mechanisms, etc.
 *
 * Emits a {Transfer} event.
 *
 * Requirements:
 *
 * - `sender` cannot be the zero address.
 * - `recipient` cannot be the zero address.
 * - `sender` must have a balance of at least `amount`.
 */