public static void Main()
int[][] arr = new int[5][];
arr[0] = new int[] { 5 };
arr[1] = new int[] { 5 , 4};
arr[2] = new int[] {5 , 4 ,3};
arr[3] = new int[] {5 , 4 ,3 , 2};
arr[4] = new int[] {5 , 4 ,3 , 2 , 1};
for (int i = 0; i < arr.Length; i++)
for (int j = 0; j < arr[i].Length; j++)
Console.Write(arr[i][j]+" ");