using System;

using System.Collections.Generic;

using System.Linq;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string error_message= "{\"2705\":\"Error importing username: 3167763, primary email: pkumar194@google.com, error: User already exists but Email does not match: pkumar194@googlee.com vs pkumar193@google.co.in\",\"10001\":\"Error importing username: 3195330, primary email: alejandra.mejia@google.com, error: User already exists but Email does not match: alejandra.mejia@google.com vs alejandra.mejia@googlee.com\"}";

        List<int> list = Regex.Matches(error_message, @"(?<=Error importing username: )\d+")

            .Cast<Match>()

            .Select(match => int.Parse(match.Value))

            .ToList();

        foreach (int i in list) Console.WriteLine(i);

    }

}