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

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner sc = new Scanner(System.in);
        BigInteger a = new BigInteger(sc.next());
        BigInteger b = new BigInteger(sc.next());
        BigInteger t = new BigInteger(sc.next());
        BigInteger power = new BigInteger("1000000007");
        BigInteger two = new BigInteger("2");
        BigInteger ans = b.add(a);
        ans = ans.divide(two);
        
        ans = ans.modPow(t,power);
        System.out.print(ans);
        
        
    }
}