MagicWeight

using System;
using System.Threading;
using System.Globalization;

class MagicDates
{
    private static int GetWeigth(DateTime date) {
        string str = date.ToString("ddMMyyyy");
        int len = str.Length;
        int[] arr = new int[len];
        char[] cArr = str.ToCharArray();

        for (int i = 0; i < len; i++){
            arr[i] = cArr[i] - '0';
        }

        int weigth = 0;
        for (int i = 0; i < len - 1; i++) {
            if (arr[i] != 0) {
                for (int j = i + 1; j < len; j++) {
                    weigth += arr[i] * arr[j];
                }
            }
        }

        return weigth;
    }

    static void Main(string[] args)
    {
        Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("en-US");

        int startYear = int.Parse(Console.ReadLine());
        int endYear = int.Parse(Console.ReadLine());
        int weigth = int.Parse(Console.ReadLine());

        DateTime startDate = new DateTime(startYear, 1, 1);
        DateTime endDate = new DateTime(endYear, 12, 31);

        bool success = false;
        for (; startDate <= endDate; startDate = startDate.AddDays(1)) {
            if (GetWeigth(startDate) == weigth) {
                Console.WriteLine(startDate.ToString("dd-MM-yyyy"));
                success = true;
            }
        }

        if(!success)
            Console.WriteLine("No");
    }
}