public override async Task Part2() { var fromNumber = Convert.ToInt32(new string(PuzzleInput.Take(6).ToArray())); var toNumber = Convert.ToInt32(new string(PuzzleInput.Skip(7).Take(6).ToArray())); var numberRange = Enumerable.Range(fromNumber, toNumber - fromNumber); var count = 0; var validNumbers = new List <int>(); foreach (var number in numberRange) { if (CheckNumberPart2(number)) { validNumbers.Add(number); } } ResultPart2 = validNumbers.Count.ToString();; }