#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


unsigned long long PowByMod (size_t d, unsigned long long t, size_t modulo)
{
	unsigned long long mod_res = 1;

	while (t)
	{
		if (t % 2 == 0)
		{
			t /= 2;
			d = (d * d) % modulo;
		}
		else
		{
			t--;
			mod_res = (mod_res * d) % modulo;
		}
	}
	return mod_res;
}


int main ()
{
	size_t a;
	size_t b;
	std::cin >> a >> b;

	size_t d = 0.5 * (a + b);

	unsigned long long t;
	std::cin >> t;

	size_t modulo_value = 1000000007;

	unsigned long long answer = PowByMod (d, t, modulo_value);

	std::cout << answer;
	return 0;
}