//This code is an updated, working version of the code Tender Termite wrote
List<List<int>> matrix = new List<List<int>>(); //Create 2d List
List<int> list1 = new List<int>();
list1.Add(4);
list1.Add(5);
matrix.Add(list1); //Insert List into matrix
List<int> list2 = new List<int>();
list2.Add(6);
list2.Add(7);
matrix.Add(list2);
int x = matrix[0][1]; //Get data from Matrix, here x is 5
matrix[0].RemoveAt(1); //Removes the 5
x = matrix[0][0]; //x is now 4
matrix.RemoveAt(0); //removes whole first row
x = matrix[0][1]; //x is now 7