#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <cassert>
using namespace std;

#define GET_ARG(a,b,c,F,...) F
#define REP3(i,s,e) for (i = s; i <= e; i++)
#define REP2(i,n) REP3 (i,0,(int)(n)-1)
#define REP(...) GET_ARG (__VA_ARGS__,REP3,REP2) (__VA_ARGS__)
#define RREP3(i,s,e) for (i = s; i >= e; i--)
#define RREP2(i,n) RREP3 (i,(int)(n)-1,0)
#define RREP(...) GET_ARG (__VA_ARGS__,RREP3,RREP2) (__VA_ARGS__)
#define DEBUG(x) cerr << #x ": " << x << endl

int main(void) {
    int i, n, c;
    cin >> n;
    vector<int> ans;
    ans.push_back(n%10);
    c = n / 10;
    RREP (i,99,10) {
        int x = i * n + c;
        ans.push_back(x%100);
        c = x / 100;
    }
    RREP (i,9,1) {
        int x = i * n + c;
        ans.push_back(x%10);
        c = x / 10;
    }
    cout << c << ".";
    RREP (i,ans.size()) cout << ans[i];
    cout << endl;
    return 0;
}