```
$ 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.
#include <Core/Defines.h>
#include <Common/hex.h>
#include <Common/PODArray.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/memcpySmall.h>
#include <Formats/FormatSettings.h>
#include <IO/WriteHelpers.h>
#include <IO/WriteBufferFromString.h>
#include <IO/BufferWithOwnMemory.h>
#include <IO/readFloatText.h>
#include <IO/Operators.h>
#include <base/find_symbols.h>
#include <stdlib.h>
#ifdef __SSE2__
    #include <emmintrin.h>
#endif
namespace DB
{
namespace ErrorCodes
{
    extern const int CANNOT_PARSE_INPUT_ASSERTION_FAILED;
    extern const int CANNOT_PARSE_ESCAPE_SEQUENCE;
    extern const int CANNOT_PARSE_QUOTED_STRING;
    extern const int CANNOT_PARSE_DATETIME;
    extern const int CANNOT_PARSE_DATE;
    extern const int INCORRECT_DATA;
}
template <typename IteratorSrc, typename IteratorDst>
void parseHex(IteratorSrc src, IteratorDst dst, const size_t num_bytes)