include

using namespace std;

int main() {
int N;
double P = 1.0;

cout << "Enter a natural number N: ";
cin >> N;
for(int i = 1; i <= N; i++) {
P *= (2.0 * i / (2.0 * i + 1));
}
cout << "The product of the first " << N << " factors is: " << P << endl;
return 0;

}

// Пример
// Ввод: 5
// Вывод: 0.146267