public void TestBiggestVerticalProduct()
 {
     int[,] testNumbers = new int[4, 4] {
         { 8, 2, 1, 1 }, { 22, 97, 45, 2 }, { 38, 15, 22, 2 }, { 8, 2, 1, 1 }
     };
     Assert.AreEqual(53504, problem11.BiggestVerticalProduct(testNumbers));
 }