using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var p = NList;
        var n = long.Parse(ReadLine());
        WriteLine(Sum(p, n));
    }
    static long Sum(int[] p, long n)
    {
        var alist = new int[] { 1, 1, 0, -1, -1, -1, 0, 1 };
        var blist = new int[] { 0, -1, -1, -1, 0, 1, 1, 1 };
        var clist = new int[] { 0, 1, 1, 1, 0, -1, -1, -1 };
        var dlist = new int[] { 1, 1, 0, -1, -1, -1, 0, 1 };
        var mod = 1_000_000_007;
        var mul = Exp(2, n / 2, mod);
        var amul = alist[n % 8] + clist[n % 8];
        var bmul = blist[n % 8] + dlist[n % 8];
        return (p[amul < 0 ? 0 : 1] * amul % mod + p[bmul < 0 ? 2 : 3] * bmul % mod + mod * 4L) % mod * mul % mod;
    }
    static long Exp(long n, long p, int mod)
    {
        long _n = n % mod;
        var _p = p;
        var result = 1L;
        if ((_p & 1) == 1) result *= _n;
        while (_p > 0)
        {
            _n = _n * _n % mod;
            _p >>= 1;
            if ((_p & 1) == 1) result = result * _n % mod;
        }
        return result;
    }
}