public class Solution {

    public int LeastBricks(IList<IList<int>> wall) {

        if (wall.Count == )

            {

                return ;

            }

            int count = ;

            Dictionary<int, int> map = new Dictionary<int, int>();

            foreach (var list in wall)

            {

                int length = ;

                for (int i = ; i < list.Count - ; i++)

                {

                    length += list[i];

                    if (!map.ContainsKey(length))

                    {

                        map.Add(length, );

                    }

                    else

                    {

                        map[length]++;

                    }

                    count = Math.Max(count, map[length]);

                }

            }

            return wall.Count - count;

    }

}