using System;

using System.Text;

public class Program

{

    private static readonly Random Rnd = new Random();

    static int x = 5;

    public static void Main() {

        String[] array = new String[x];

        for (int i = 0; i < x; i++) {

            array[i] = randomIMEIgenerator();

        }

        foreach(var s in array) {

            Console.WriteLine(s);

        }

    }

    public static string randomIMEIgenerator() {

        var builder = new StringBuilder();

        while (builder.Length < 15) {

            builder.Append(Rnd.Next(10).ToString());

        }

        return builder.ToString();

    }

}