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

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 = new BigInteger(in.next());
        
        
        BigInteger virusPop;
        BigInteger scale = BigInteger.valueOf(10)
        		.pow(9).add(BigInteger.valueOf(7));
        
        virusPop = BigInteger.valueOf((a+b)/2).modPow(t, scale);
        
        System.out.println(virusPop.mod(scale));
    }
}