function buy(uint256 _amount) external {
// ...
            trayTiledata[j] = _drawing(uint256(lastHash));
// ...
}
function _drawing(uint256 _seed) private pure returns (TileData memory tileData) {
// ...
            if (tileData.fontClass == 7) {
                // Set seed for Zalgo to ensure same characters will be always generated for this tile
                uint256 zalgoSeed = Utils.iteratePRNG(_seed);
                tileData.characterModifier = uint8(zalgoSeed % 256);
// ...
}
} else if (_fontClass == 7) {
    // Zalgo
    uint8 asciiStartingIndex = 97;
    uint256 numAbove = (_characterModifier % 7) + 1;
    // We do not reuse the same seed for the following generations to avoid any symmetries, e.g. that 2 chars above would also always result in 2 chars below
    _characterModifier = iteratePRNG(_characterModifier);
    uint256 numMiddle = _characterModifier % 2;
    _characterModifier = iteratePRNG(_characterModifier);
    uint256 numBelow = (_characterModifier % 7) + 1;
    bytes memory character = abi.encodePacked(bytes1(asciiStartingIndex + uint8(_characterIndex)));
    for (uint256 i; i < numAbove; ++i) {
        _characterModifier = iteratePRNG(_characterModifier);
        uint256 characterIndex = (_characterModifier % ZALGO_NUM_ABOVE) * 2;
        character = abi.encodePacked(
            character,
            ZALGO_ABOVE_LETTER[characterIndex],
            ZALGO_ABOVE_LETTER[characterIndex + 1]
        );
    }
    for (uint256 i; i < numMiddle; ++i) {
        _characterModifier = iteratePRNG(_characterModifier);
        uint256 characterIndex = (_characterModifier % ZALGO_NUM_OVER) * 2;
        character = abi.encodePacked(
            character,
            ZALGO_OVER_LETTER[characterIndex],
            ZALGO_OVER_LETTER[characterIndex + 1]
        );
    }
    for (uint256 i; i < numBelow; ++i) {
        _characterModifier = iteratePRNG(_characterModifier);
        uint256 characterIndex = (_characterModifier % ZALGO_NUM_BELOW) * 2;
        character = abi.encodePacked(
            character,
            ZALGO_BELOW_LETTER[characterIndex],
            ZALGO_BELOW_LETTER[characterIndex + 1]
        );
    }
    return character;
} else {
