prvi

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

int main() {
	int N = 0;
	do {
		cout << "Upisite N :D \n";
		cin >> N;
	}while(N < 1);

	if(N == 1) {
		cout << 1;
		return 0;
	} else if (N == 2) {
		cout << 2;
		return 0;
	}

	double e = 2;
	double nesto = 2;

	for(int i = 0; i < N-2 ; ++i) {
		nesto = 1;
		for(int j = 1; j <= i+2; ++j)
			nesto *= j;
		e += (1/nesto);
	}

	cout << setprecision(12) <<  e;
	return 0;
}