We increase ~X~ by ~1~ until we've found a solution. If we don't find one in ~1\,000\,000~ iterations, then there is surely no such number and we output zero. What remains is to find a simple procedure to check if two integers ~X~ and ~Y~ consist of the same digits.

Separating an integer into digits can be done by repeatedly observing the last digit (remainder when dividing it by ~10~) and dividing the number by ~10~, while the number is not zero.

To check if ~X~ and ~Y~ consist of the same digits, we count how many times each of the ~10~ digits appears in each number. If the counts match for all digits, the numbers consist of the same digits.