Console.WriteLine("请输入天数");
            int day = Convert.ToInt32(Console.ReadLine());

            int d = day / 7;
            int d1 = day % 7;
            int sum = 0;
            int r = 0;
            sum = d * 28;
            for (int i = 1; i <=7; i++)
            {
                for (int j = i; j <=d1; j++)
                {
                   r += j;
                }
                i = 7;
            }
            Console.WriteLine(sum+r);
            Console.ReadLine();

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