gistfile1.txt

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

internal class Program
{
    static void Main(string[] args)
    {
        Random random = new Random();
        int number = rand.Next(1, 100);
        int result = 0;
        int multipleToThree = 3;
        unt multipleToFive = 5;
        
        for(int i = 0; i <= number; i++)
        {
            if(i % three == 0 || i % five == 0)
            {
                result += i;
            }
        }
        Console.WriteLine("Сумма чисел, кратных 3 или 5, равна " + result);
    }
}