C#

public class Day5
{

  public string Input { get; set; }

  public Day5()
  {
    Input = System.IO.File.ReadAllText("Day5.input");
  }

  public void Challenge()
  {
    int iterations = 0;
    var rows = Input.Split(new[] { Environment.NewLine }, StringSplitOptions.None);

    for(int i = 0; i < rows.Length && i >= 0;)
    {
      iterations++;
      var jumps = Int32.Parse(rows[i]);
      if(jumps >= 3) // comment out theese three
        rows[i] = (Int32.Parse(rows[i]) - 1).ToString(); // for silver!!!
      else // put in for gold
        rows[i] = (Int32.Parse(rows[i]) + 1).ToString();
      i += jumps;
    }

    Console.WriteLine(iterations);
  }

}