#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include <iostream>
#include <cstring>
#include <algorithm>
#include <limits.h>
#include <cmath>
#include <cstdio>
#include <vector>
#include <set>
#include <string>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
using namespace std;

typedef long long ll;
typedef unsigned long long ull;

int test = 0;
/* ここからが本編 */

int main(void)
{
  int i,j,k,l;
  int n;
  cin >> n;
  double rep = 1;
  rep(i,n) rep *= 3.0/4;
  printf("%.20lf\n",rep);
  
  return 0;
}