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

public class Solution {
    public static final BigInteger MOD_VALUE = BigInteger.valueOf(1_000_000_007);

    public static int getAnswer(int a, int b, BigInteger t) {
        int x = (a + b) / 2;

        BigInteger bigX = BigInteger.valueOf(x);
        BigInteger answer = bigX.modPow(t, MOD_VALUE);

        return answer.intValue();
    }

    public static void main(String[] args) {
        try (Scanner in = new Scanner(System.in);) {
            int a = in.nextInt();
            int b = in.nextInt();
            BigInteger t = in.nextBigInteger();

            System.out.println(getAnswer(a, b, t));
        }
    }
}