Use byte array, worked in my case. Passed all 3 tests with that sln

Cuz it's not a 2d array, it's just an array(s) in an array.

Dude, it was created by fucked up pearson who likes torture people. That stupid condition made me suffer for 3 hours.
if (array.Length == 1)
{
return array[0];
}

Че блять за хуйню придумали!? Какой-то блядский массив вида [[]] вернуть им надо, когда массив пустой. Почему блять просто не вернуть null или []? Я ни хера создателей не понимаю. На кой ляд они захуярили зубчатый массив вместо обычного двумерного вида [,]? Ебанутая ката, как и ее создатели.

Why do you use int [][] instead of int [,] in c#? I don't get it.

Doesn't work because of 255 character is interpreterd by C# as 63, that's why test 1 just loops and I can't go futher. Input gives ÿ character. Idk what to do. Any ideas?