```
$ 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/Types.h>
#include <Core/DecimalFunctions.h>
#include <Core/UUID.h>
#include <Common/Allocator.h>
#include <Common/Exception.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/Arena.h>
#include <Common/intExp.h>
#include <Formats/FormatSettings.h>
#include <IO/CompressionMethod.h>
#include <IO/ReadBuffer.h>
#include <IO/ReadBufferFromMemory.h>
#include <IO/VarInt.h>
#include <DataTypes/DataTypeDateTime.h>
#include <double-conversion/double-conversion.h>
static constexpr auto DEFAULT_MAX_STRING_SIZE = 1_GiB;
namespace DB
{
template <typename Allocator>
struct Memory;
namespace ErrorCodes
{
    extern const int CANNOT_PARSE_DATE;
    extern const int CANNOT_PARSE_DATETIME;
    extern const int CANNOT_PARSE_UUID;
    extern const int CANNOT_READ_ARRAY_FROM_TEXT;
    extern const int CANNOT_PARSE_NUMBER;
    extern const int INCORRECT_DATA;
}
inline char parseEscapeSequence(char c)