#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>

using namespace std;

long long int power (long long int x, long long int y) {
	
	long long int res = 1;

	while (y > 0) {

		if (y & 1) 	// y is odd
			res = res * x;

		y = y >> 1; // y = y/2
		x = x * x;	// x = x^2
	}

	return res;	
}

long long int powermod (long long int x, long long int y, long long int z) {

	long long int res = 1;

	while (y > 0) {

		if (y & 1) 	// y is odd
			res = (res * x) % z;

		y = y >> 1; // y = y/2
		x = (x * x) % z;	// x = x^2
	}

	return res;
}

int main(int argc, char const *argv[]) {
	
	ios::sync_with_stdio(0);	
	
	long long int a, b, t;

	long long int x, y;

	cin >> a >> b >> t;

	y = power(10, 9) + 7;
	x = powermod(0.5 * (a + b), t, y);
	
	cout << x % y << '\n';
	
	return 0;
}