#include <iostream>
#include <fstream>
using namespace std;


int main(void)

{
	double resistor=0.0;

    const int maxSize=200;
	double array[maxSize];
    int num=0;
    int x;
	double value;
	cout<<"please enter the number of the resistors: "<<endl;
	cin>>num;
	for(x=1;x<=num;x++)
	{
        
		cout<<"Please enter the value for R "<<x<<endl;
		cin>>value;
		
	   array[x]=value;
	}

for (int n=num/2;n<1;n--)
{

resistor= (array[2*n-1]+array[2*n])*array[2*n-2]/(array[2*n-2]+array[2*n]+array[2*n-1]);

array[2*n-2]=resistor;

}

	resistor = resistor+ array[1];

		if(num==1)
	{
		resistor=array[1];
	}
			if (num==2)
	{

	resistor=array[1]+array[2];
	}

	if(num==4)
	{
		resistor=((array[4]+array[3])*array[2]/(array[2]+array[3]+array[4]))+array[1];
	}
	
     cout<<"the value of equivlent resisitance is= "<<resistor<<endl;
	 
	return 0;
}