public class Solution
{
    public bool AreSimilar(int[][] mat, int k)
    {
        var answer = true;
        var shift = -k;
        for (var i = 0; i < mat.Length; i++)
        {
            var len = mat[i].Length;
            for (var j = 0; j < len; j++)
            {
                var idx = ((j + shift) % len + len) % len;
                answer &= mat[i][j] == mat[i][idx];
            }
            shift = -shift;
        }
        return answer;
    }
}