Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func read() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	sc.Split(bufio.ScanLines)
	for sc.Scan() {
		n, _ := strconv.ParseFloat(sc.Text(), 64)
		ans := n
		sum := n
		for i := 2; i <= 10; i++ {
			if i%2 == 0 {
				ans *= 2
				sum += ans
			} else {
				ans /= 3
				sum += ans
			}
		}
		fmt.Println(sum)
	}
}

C++: #include<iostream>
#include<math.h>
#include<string>
#include<vector>
#include<algorithm>
#include<queue>
#include<map>
#include<iomanip>
using namespace std;
#define INF 1<<20

struct edge{
	int to;
	int cost;
	edge() {};
	edge(int a, int b) {
		to = a;
		cost = b;
	}
};

struct Node {
	int pos;
	int cost;
	Node() {};
	Node(int a, int b) {
		pos = a;
		cost = b;
	}
	bool operator <(const Node& rhs) const {
		return cost > rhs.cost;
	}
};

void dijkistra(int st, int TO,int V,vector<vector<edge> > graph) {
	priority_queue<Node> q;
	vector<int> d(V);
	for (int i = 0;i < V;i++) {
		d[i] = INF;
	}
	d[st] = 0;
	q.push(Node(st, 0));
	while (!q.empty()) {
		Node s = q.top(); q.pop();
		int pos = s.pos;
		for (int i = 0;i < graph[pos].size();i++) {
			int to = graph[pos][i].to;
			int cost = graph[pos][i].cost;
			if (d[pos] + cost < d[to]) {
				d[to] = d[pos] + cost;
				q.push(Node(to, d[to]));
			}

		}
	}
	cout << d[TO] << endl;
}
int partition(int A[],int p, int r) {
	int x = A[r];
	int i = p - 1;
	for (int j = p;j < r;j++) {
		if (x >= A[j]) {
			i = i + 1;
			swap(A[i], A[j]);
		}
	}
		swap(A[i + 1], A[r]);
		return i + 1;
}
void quicksort(int A[], int p, int r) {
	if (p < r) {
		int q = partition(A, p, r);
		quicksort(A, p, q-1);
		quicksort(A, q + 1, r);
	}
}

int getNumberOfCoin(int C[],int n,int m) {
	int T[50000];
	for (int j = 0;j <= n;j++) {
		T[j] = INF;
	}
	T[0] = 0;
	for (int i = 0;i < m;i++) {
		for (int j = 0;j <= n;j++) {
			if (j - C[i] >=0  ) {
				T[j] = min(T[j], T[j - C[i]] + 1);
			}
		}
	}
	return T[n];
}
int knapsack(int w, int n,int* v,int* ww) {
	int W[101][10001];
		for (int j = 0;j <= w;j++) {
			W[0][j] = 0;
		}
	for (int i = 0;i < n;i++) {
		for (int k = 0;k < n;k++){
			for (int j = 0;j <= w;j++) {
				if (j - ww[k] < 0) {
					W[i + 1][j] = W[i][j];
				}
				if (j - ww[i] >= 0) {
					W[i + 1][j] = max(W[i][j], W[i][j - ww[k]] + v[k]);

				}
			}
		}
	}
	return W[n][w];
}
int fib(int n) {
	vector<int> v(n+1);
	v[0] = 1;
	v[1] = 1;
	for (int i = 2;i < n+1;i++) {
		v[i] = v[i - 2] + v[i - 1];
	}
	return v[n];
}
int isPrime(int x) {
	if (x <= 1) return false;
	if (x>2 && x % 2 == 0) return false;
	for (int i = 2;i <= sqrt(x);i++) {
		if (x%i == 0) {
			return false;
		}
	}
	if (x == 2) return true;
	return true;
}
vector<long long int> a;
void Prime(int x) {
	vector<int> prime(x+1,1);
	int num = 2;
	while (num <= sqrt(x)) {
		a.push_back(num);
		for (int i = 2;i <= x / num;i++) {
			prime[num*i] = 0;
		}
		num++;
		while (prime[num] == 0)
			num++;
	}
	int count = 0;
	for (int i = 2;i < x + 1;i++) {
		if (prime[i] == 1) count++;
	}
	
}
int main() {
	double a;
	while (cin >> a) {
		double ans[10];
		ans[0] = a;
		double sum = a;
		for (int i = 1;i < 10;i++) {
			if (i % 2 == 0) ans[i] = ans[i - 1] / 3;
			else ans[i] = 2 * ans[i - 1];
			sum += ans[i];
		}
		cout <<setprecision(9) <<sum << endl;
	}
	
	}

C++: #include <cstdio>
using namespace std;
float sequence(float a) {
  float s[10];
  float sum = 0;
  for(int i = 0; i < 10; ++i) {
	if(i == 0) {
	  s[i] = a;
	}
	else if(i % 2) { // odd
	  s[i] = s[i - 1] * 2;
	}
	else {
	  s[i] = s[i - 1] / 3;
	}
	sum += s[i];
  }
  return sum;
}
int main() {
  float a;
  while(~scanf("%f", &a)) {
	printf("%f\n", sequence(a));
  }
  return 0;
}

C++: #include <iostream>
#include <iomanip>
using namespace std;

int main(){
        double a;
        double sum;
        while(cin >> a){
                sum = 0;
                for(int i = 1; i <= 10; i++){
                        sum += a;
                        if(i % 2 == 0){
                                a /= 3;
                        } else{
                                a *= 2;
                        }
                cout << setprecision(10);
                }
                cout << sum << endl;
        }
        return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int main(){
  double a;
  while(cin >> a){
    double sum = a;
    double now = a;
    for(int i=2;i<=10;i++){
      if(i%2 == 0){
	now *= 2.0;
      } else {
	now /= 3.0;
      }
      sum += now;
    }
    cout << sum << endl;
  }
}

C++: #include<iostream>
#include<iomanip>
using namespace std;
double a, sum;
int main() {
	while (cin >> a) {
		sum = a;
		for (int i = 2; i < 11; i++) {
			if (i % 2 == 0) {
				a *= 2;
			}
			else {
				a /= 3;
			}
			sum += a;
		}
		cout << fixed << setprecision(15) << sum << endl;
	}
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<cstdio>
#include<sstream>
#include<algorithm>
#include<cmath>
#include<map>
#include<functional>
#include<queue>
#include<stack>
#include<set>
using namespace std;


int main(){
	double a[10];
	double now,sum;
	while(cin>>now){
	for(int i=0;i<10;i++)a[i]=0.0;
	a[0]=now;
	sum=a[0];
		for(int i=1;i<10;i++){
			if(i%2==1)a[i]=a[i-1]*2;//??¶??°
			else a[i]=a[i-1]/3;
			sum+=a[i];
		}
		printf("%.15lf\n",sum);
	}
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cstring>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <numeric>
#include <utility>
#include <iomanip>
#include <algorithm>
#include <functional>
using namespace std;

typedef long long ll;
typedef vector<int> vint;
typedef vector<long long> vll;
typedef pair<int,int> pint;
typedef pair<long long, long long> pll;

#define MP make_pair
#define PB push_back
#define ALL(s) (s).begin(),(s).end()
#define EACH(i, s) for (__typeof__((s).begin()) i = (s).begin(); i != (s).end(); ++i)
#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T1, class T2> ostream& operator << (ostream &s, pair<T1,T2> P) 
{ return s << '<' << P.first << ", " << P.second << '>'; }
template<class T> ostream& operator << (ostream &s, vector<T> P) 
{ for (int i = 0; i < P.size(); ++i) { if (i > 0) { s << " "; } s << P[i]; } return s << endl; }
template<class T1, class T2> ostream& operator << (ostream &s, map<T1,T2> P) 
{ EACH(it, P) { s << "<" << it->first << "->" << it->second << "> "; } return s << endl; }


double a;

int main() {
    while (cin >> a) {
        double res = a;
        for (int i = 2; i <= 10; ++i) {
            if (i & 1) a /= 3;
            else a *= 2;
            res += a;
        }
        cout << fixed << setprecision(9) << res << endl;
    }
    
    return 0;
}

C++: #include<iostream>
#include<stdio.h>
using namespace std;
int main(){
  double d;
  while(cin >> d){
    double a=d,b=0;
    for(int i=0;i<10;i++){
      b+=a;
      if(i%2==1) a/=3.0;
      else a*=2.0;
      //cout << a << endl;
    }
    //cout << b << endl;
    printf("%.10lf\n",b);
  }
}