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

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        BigInteger a = new BigInteger(scan.next());
        BigInteger b = new BigInteger(scan.next());
        BigInteger t = new BigInteger(scan.next());
        BigInteger e = BigInteger.TEN.pow(9).add(BigInteger.valueOf(7));
        
        BigInteger expected = a.add(b).divide(BigInteger.valueOf(2)).modPow(t, e);
        
        System.out.println(expected);
    }
}