#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	double e=1.0,s=1.0;
	cin>>n;
	for(int i=1;i<=n;i++){
		e*=i;
		s+=1/e;
	}
	cout<<fixed<<setprecision(10)<<s<<endl;
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main(){
    double a[20];
    a[0] = 1;
    a[1] = 1;
    for(int i = 2;i < 16;i++){
        a[i] = a[i - 1] / i;
    }
    int n;
    cin >> n;
    double e = 0;
    for(int i = 0;i <= n;i++){
        e += a[i];
    }
    cout << fixed << setprecision(10) << e << endl;
    return 0;
}