using System;

using System.Net.Http;

public class Program

{

    public static void Main()

    {

        var client = new HttpClient();

        var result = client.GetAsync("https://slack.com/api/files.list?token=xoxp-13341686499-13348148593-278905836865-6fb5a0bf4fa7b6831d3a9e68063b63ba&ts_to=1509494400d&pretty=1").GetAwaiter().GetResult();

​

        var response = result.Content.ReadAsStringAsync().GetAwaiter().GetResult();

        Console.Write(response);    

    }

}