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) {   
        Scanner in = new Scanner(System.in);
        BigInteger rateA = new BigInteger(in.next());
        BigInteger rateB = new BigInteger(in.next());
        BigInteger t = new BigInteger(in.next());
        BigInteger m = new BigInteger("1000000007");
        BigInteger a = ((rateA.add(rateB)).divide(new BigInteger("2"))).modPow(t,m);
        System.out.println(a);
    }
}