using System;
namespace ConsoleApplication1
{
class Program
{
static float OuShu(int n)
{
float sum = 0f;
for (int i = 2; i <= n; i++)
{
if (i % 2 == 0)
{
sum = sum + 1 / (float)i;
}
}
return sum;
}
static float JiShu(int n)
{
float sum = 0f;
for (int i = 1; i <= n; i++)
{
if (i % 2 != 0)
{
sum = sum + 1 / (float)i;
}
}
return sum;
}
static void Main(string[] args)
{
Console.WriteLine("请输入一个非负整数");
int n = Convert.ToInt32(Console.ReadLine());
if (n % 2 == 0)
{
//偶数
Console.WriteLine(OuShu(n));
}
else
{
//奇数
Console.WriteLine(JiShu(n));
}
}
}
}