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 scanner = new Scanner(System.in);

		int a, b;
		BigInteger t = null;
		BigInteger r = null;
		
		String m = "1000000007";
		a = scanner.nextInt();
		b = scanner.nextInt();
		t = scanner.nextBigInteger();
		
		
		r = BigInteger.valueOf((a + b)/2);
		r = r.modPow(t, new BigInteger(m));	
		
		System.out.println(r);
		
		scanner.close();		
    }
}