public class Solution {
    public int[,] MatrixReshape(int[,] nums, int r, int c) {
        var row = nums.GetLength(0);
            var col = nums.GetLength(1);

            if (row * col != r * c)
            {
                return nums;
            }
            else
            {
                var ary = new int[r, c];
                var list = new List<int>();

                for (int i = 0; i < row; i++)
                {
                    for (int j = 0; j < col; j++)
                    {
                        list.Add(nums[i, j]);
                    }
                }

                var k = 0;
                for (int i = 0; i < r; i++)
                {
                    for (int j = 0; j < c; j++)
                    {
                        ary[i, j] = list[k++];
                    }
                }

                return ary;
            }
    }
}