#include <iostream>
using namespace std;



double e(int x, int n)
{
    static double s;
    if (n==0)
        return s;
    else
        s = 1 + x*(s/n);
        return e(x, n-1);
}


int main() {
    double sum= e(1,10);
    cout << sum;
    return 0;
}