#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <numeric>
#include <queue>
#include <stack>
#include <map> 
#include <set>
#include <string>
#include <functional>
#include <list>
#include <random>
#include <time.h>
#include <iomanip>
#include <assert.h>
#include <numeric>
#define int long long
#define ll long long
#define double long double
#define mod 1000000007
#define MAXN (int)1e+5 * 2+1
#define LL_MAX 9223372036854775807	//ない環境用
#define LL_HALFMAX 9223372036854775807 / 2	//ない環境用
#define MIN -(9223372036854775807 / 2)
#define INF 9223372036854775807 / 2
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
#define REPS(i,x) for(int i=1;i<=(int)(x);i++)
#define RREP(i,x) for(int i=((int)(x)-1);i>=0;i--)
#define RREPS(i,x) for(int i=((int)(x));i>0;i--)
#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define mp make_pair


using namespace std;

std::mt19937 mt((int)time(0));

int dx[4] = { 0, 1, 0, -1 }; // x軸方向への変位
int dy[4] = { 1, 0, -1, 0 }; // y軸方向への変位

using Weight = int;
using Flow = int;
struct Edge {
	int src, dst;
	Weight weight;
	Flow cap;
	Edge() : src(0), dst(0), weight(0) {}
	Edge(int s, int d, Weight w) : src(s), dst(d), weight(w) {}
};
using Edges = std::vector<Edge>;
using Graph = std::vector<Edges>;
using Array = std::vector<Weight>;
using Matrix = std::vector<Array>;

void add_edge(Graph &g, int a, int b, Weight w = 1) {
	g[a].emplace_back(a, b, w);
	g[b].emplace_back(b, a, w);
}
void add_arc(Graph &g, int a, int b, Weight w = 1) { g[a].emplace_back(a, b, w); }

bool chkBad(string s) {
	string s1 = s.substr(0, 3), s2 = s.substr(1, 3);

	if (s1 == "AGC" || s1 == "ACG" || s1 == "GAC") return true;
	if (s2 == "AGC" || s2 == "ACG" || s2 == "GAC") return true;
	if (s[0] == 'A' && s[2] == 'G' && s[3] == 'C') return true;
	if (s[0] == 'A' && s[1] == 'G' && s[3] == 'C') return true;
	return false;
}

vector<map<string , int>> v;
char chars[] = "ACGT";
int pow2[63];
signed main() {
	int N;
	cin >> N;

	for (int i = 0; i <= 100; i++) {
		map<string, int> ma;
		v.push_back(ma);
	}

	for (int i = 0; i < 4; i++) {
		for (int j = 0; j < 4; j++) {
			for (int k = 0; k < 4; k++) {
				string s = "";
				string t = "";

				t += chars[i];
				t += chars[j];
				t += chars[k];
				if (t == "AGC" || t == "ACG" || t == "GAC") continue;

				s += chars[i];
				s += chars[j];
				s += chars[k];
				v[3][s]++;

			}
		}
	}

	//debug
	/*
	map<string, int> m;
	for (int i = 0; i < 4; i++) {
		for (int j = 0; j < 4; j++) {
			for (int k = 0; k < 4; k++) {
				for (int l = 0; l < 4; l++) {
					
						string s = "";
						string t = "";

						t += chars[i];
						t += chars[j];
						t += chars[k];
						t += chars[l];

						if (chkBad(t)) continue;

						s += chars[j];
						s += chars[k];
						s += chars[l];
						m[s]++;
				}

			}
		}
	}
	*/

	for (int i = 4; i < 101; i++) {
		for (auto p : v[i-1]) {
			for (int j = 0; j < 4; j++) {
				string s = p.first;
				string t = s;
				t += chars[j];
				if (chkBad(t)) continue;
				string u = t.substr(1, 3);
				v[i][u] += v[i-1][s];
				v[i][u] %= mod;

			}
		}
	}

	int ans = 0;
	for (auto p : v[N]) {
		ans += p.second;
		ans %= mod;
	}
	cout << ans << "\n";

	return 0;
}

Measured memory_bytes: 896