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

public class Solution {

    public static void main(String[] args) {
     Scanner in = new Scanner(System.in);
        
        double a = in.nextDouble();
        double b = in.nextDouble();
        BigInteger t = in.nextBigInteger();
        
        Long summations = (long)((a+b)/2);
        BigInteger expected = BigInteger.valueOf(summations);
        BigInteger constModi = BigInteger.valueOf(1000000007);
        
        BigInteger res = expected.modPow(t , constModi);
        System.out.println(res.toString());
    }
}