Fix fancy number

[dimaush]

Добавил в тесты числа с цифрами 2, 3, 4, 5, 7 и отрицательные (эталонное решение проверяло отсутствие других цифр, в то время как в тестах не было ни одной проверки на наличие этой проверки). Также изменил тип входа со строкового на целый (всё равно чисел по модулю больше чем 10^9 в тестах нет).

[vtm9]

The additional unsupported-digit tests are useful, but the new limits line is missing its closing $, so the constraint will not render as math.

The PR also changes the input from a decimal string to an integer, removing leading-zero representations such as "00", and introduces negative inputs without specifying how a minus sign behaves under rotation. The old task deliberately tested leading-zero strings. These are contract changes beyond adding coverage.

Please retain the string signature while broadening the allowed digits and adding the new negative cases only if their behavior is explicitly defined, or provide a clear reason for the integer contract change and define it completely. Fix the math delimiter in either case. All 30 submitted asserts pass.