using namespace std; 
#include<iostream>

int main()
{
double s=1,i; int n;
 
cout<<"Enter n(n=2k):";
cin>>n;
if(n%2>0)
	{
	cout<<"the number you entered is odd";
	cin>>n;
	}
	else
	{
for(i=2;i<=n;i+=2)
	{
	s+=(i+1)/i;
	}
cout<<"sum of them="<<s;
	 }
  
}