#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
 
using namespace std;
 
#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define clr(a, b) memset((a), (b) ,sizeof(a))
 
#define MOD 1000000007

long long dp[4][100];

int main(){
  int x;
  cin>>x;
  dp[0][0]=3;
  dp[1][0]=3;
  dp[2][0]=3;
  dp[3][0]=1;
  rep(i,1,100){
    rep(j,0,10){
      if(j==3){
        dp[3][i]+=dp[0][i-1];
        dp[3][i]+=dp[1][i-1];
        dp[3][i]+=dp[2][i-1];
        dp[3][i]+=dp[3][i-1];
      }
      else{
        dp[0][i]+=dp[(9-j)%3][i-1];
        dp[1][i]+=dp[(10-j)%3][i-1];
        dp[2][i]+=dp[(11-j)%3][i-1];
        dp[3][i]+=dp[3][i-1];
      }
    }
  }
  cout << dp[0][x-1]+dp[3][x-1]-1 << endl;
  return 0;
}