#include<bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(v) v.begin(),v.end()
#define PI acos(-1)
typedef  long long ll;
ll MOD=1000000007;

ll gcd(ll x,ll y){
   if(y==0) return x;
   else return gcd(y,x%y);
}
ll lcm(ll x,ll y){
   return x/gcd(x,y)*y;
}

int main(){
   int k;
   cin>>k;
   double ans=0;
   if(k==0){
      cout<<0<<endl;
      return 0;
   }
   for(int i=1;i<=100;i++){
      double tmp=sin(k*i)/pow(i,i);
      //cout<<tmp<<" "<<ans<<endl;
      if(abs(tmp)<0.000000001){
         break;
      }
      ans+=tmp;
   }
   cout<<setprecision(10)<<ans<<endl;
   
   return 0;
}