using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication8
{
    class Program
    {
        static void Main(string[] args)
        {
            int x;
            x = Convert.ToInt32 (Console.ReadLine());
            if ((x > 1 & x <= 4)
            {
                Console.WriteLine("few");
            }
            if (x > 5 & x<= 9)
            {
                Console.WriteLine("several");
            }
            if (x > 10 & x <= 19)
            {
                Console.WriteLine("pack");
            }
            if (x > 20 & x <= 49)
            {
                Console.WriteLine("lots");
            }
            if (x > 50 & x <= 99)
            {
                Console.WriteLine("horde");
            }
            if (x > 100 & x <= 249)
            {
                Console.WriteLine("throng");
            }
            if (x > 250 & x <= 499)
            {
                Console.WriteLine("swarm");
            }
            if (x > 500 & x <= 499)
            {
                Console.WriteLine("zounds");
            }
            if (x > 1000)
            {
                Console.WriteLine("legion");
            }
        }
    }
}

Да что тут не так?

Edited by author 18.04.2018 23:36

Edited by author 18.04.2018 23:37

У вас везде > вместо >=.
Ну и тут отдельная ошибка if (x > 500 & x <= 499)