using System;
using System.Collections.Generic;
using System.IO;
using System.Numerics;

class Solution {
    static void Main(String[] args) {
        int[] arr = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
        BigInteger t1 = new BigInteger(arr[0]);
        BigInteger t2 = new BigInteger(arr[1]);
        int n = arr[2];

        Dictionary<int, BigInteger> dict = new Dictionary<int, BigInteger>();
        dict.Add(1, t1);
        dict.Add(2, t2);

        Console.WriteLine(fib(n, dict));
    }

    static BigInteger fib(int n, Dictionary<int, BigInteger> dict) {
        if(dict.ContainsKey(n))
            return dict[n];

        BigInteger tn = fib(n-2, dict) + fib(n-1, dict) * fib(n-1, dict);
        dict.Add(n, tn);
        return tn;
    }
}