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);
        int a = sc.nextInt();
        int b = sc.nextInt();
        int t = sc.nextInt();
        
        int n=1;
        for(int i=0; i < t; i++){
            n =(int) (0.5*a + 0.5*b)*n;
        }
        
        int m = 1000000007;
       System.out.println(n%m);
        
    }
}