import java.math.BigInteger;
import java.util.Scanner;

/**
 * Created by mayur on 26/7/16.
 */

public class Solution {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();
        BigInteger t = in.nextBigInteger();
        new Solver().solve(a, b, t);
    }
}

class Solver {

    public void solve(int a, int b, BigInteger t) {
        BigInteger mod = BigInteger.valueOf(1_000_000_007);
        BigInteger ans;
        ans = BigInteger.valueOf(a).add(BigInteger.valueOf(b));
        ans = ans.modPow(t, mod);
        BigInteger div = BigInteger.valueOf(2).modPow(t, mod);
        BigInteger fin = ((ans.mod(mod)).multiply(div.modInverse(mod))).mod(mod);
        System.out.println(fin);

    }
}