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

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        String t = scan.next();
        
        BigInteger time = new BigInteger(t);
        int growth = (a + b) / 2;
        
        BigInteger bigGrowth = new BigInteger(Integer.toString(growth));
        
        BigInteger mod = new BigInteger("1000000007");
        BigInteger result = bigGrowth.modPow(time,mod);
        System.out.println(result.toString());
    }
}