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

public class Solution {

    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);  // Reading from System.in
        BigInteger a = reader.nextBigInteger(); // Scans the next token of the input as an int.
        BigInteger b = reader.nextBigInteger(); // Scans the next token of the input as an int.
        BigInteger ms = reader.nextBigInteger(); // Scans the next token of the input as an int.
        BigInteger mod = BigInteger.valueOf(1000000007);
        System.out.println(a.add(b).divide(BigInteger.valueOf(2)).modPow(ms, mod) ) ;
    }
}