using System.Numerics;
using System;

public class Hello
{
    public static int MOD = 1000000007;
    static void Main()
    {
        var n = long.Parse(Console.ReadLine().Trim());
        getAns(n);
    }
    static void getAns (long n)
    {
        var ans = BigInteger.ModPow(3, n - 1, MOD);
        if (n % 2 == 0) ans++;
        else ans--;
        ans *= 3;
        ans %= MOD;
        var inv4 = ModInverse(4, MOD);
        ans *= inv4;
        ans %= MOD;
        Console.WriteLine(ans);
    }
    public static BigInteger ModInverse(BigInteger a, BigInteger m)
    {
        return BigInteger.ModPow(a, m - 2, m);
    }
}