#include <iostream>
#include <string>
int main() {
        std::string s = "";
        double e = 0.0;
        double f = 1.0;
        for(int i = 1; i <= 100000; i++) {
                s += "teste";
                e += 1.0/f;
                f *= i;
        }
        std::cout << e << std::endl;
        return 0;
}