5.02

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


double pre[20];

double pow(double n, double k)
{
    double res = 1; 
    for (int i = 1; i <= k; i++)
        res *= n;

    return res;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    double x; cin >> x;

    double sum = x;

    for (int i = 1; i <= 30; i++)
    {
        double t = pow(-1, i)*pow(x, 2*i+1);
        for (double j = 1; j <= 2*i+1; j++)
            t /= j;
        sum += t;
    }

    cout << setprecision(4) << fixed << sum;


    
   

    return 0;
}