```
$ echo '20210101,A' | clickhouse-local --input-format CSV --structure 'd Date, s String' --query "SELECT * FROM table"
Code: 27. DB::Exception: Cannot parse input: expected ',' before: '20210101,A\n': 
Row 1:
Column 0,   name: d, type: Date,   ERROR: text "20210101,A" is not like Date

: While executing ParallelParsingBlockInputFormat: While executing File. (CANNOT_PARSE_INPUT_ASSERTION_FAILED)
```

**How to solve**

Disambiguate while parsing by absense of separators between YYYY-MM-DD.
{
    size_t src_pos = 0;
    size_t dst_pos = 0;
    for (; dst_pos < num_bytes; ++dst_pos, src_pos += 2)
        dst[dst_pos] = unhex2(reinterpret_cast<const char *>(&src[src_pos]));
}
void parseUUID(const UInt8 * src36, UInt8 * dst16)
{
    
    parseHex(&src36[0], &dst16[0], 4);
    parseHex(&src36[9], &dst16[4], 2);
    parseHex(&src36[14], &dst16[6], 2);
    parseHex(&src36[19], &dst16[8], 2);
    parseHex(&src36[24], &dst16[10], 6);
}
void parseUUIDWithoutSeparator(const UInt8 * src36, UInt8 * dst16)
{
    
    parseHex(&src36[0], &dst16[0], 16);
}
/** Function used when byte ordering is important when parsing uuid
 *  ex: When we create an UUID type
 */
void parseUUID(const UInt8 * src36, std::reverse_iterator<UInt8 *> dst16)