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();