#include <bits/stdc++.h>
#define be(v) (v).begin(),(v).end()
#define pb(q) push_back(q)
typedef long long ll;
using namespace std;
const ll mod=1000000007, INF=(1LL<<60);
#define doublecout(a) cout<<fixed<<setprecision(10)<<a<<endl;

int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    double ans = 0;
    for(double i=1.0;i<=100;i+=1.0){
        double num = 1.0 / i;
        ans += pow(num, n);
    }
    doublecout(ans);
    return 0;
}