public static void Main()
string input = "17.644886;87.427452;51.513859;121.296410;+0.481;;89.176285;47.627792;123.045242;81.496758;+0.524;;";
var output1 = input.Split(new[] { ";;" }, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Split(';')).ToArray();
foreach (var item in output1[0])
Console.WriteLine(Math.Round(Convert.ToDouble(item), 2));