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

public class Solution {

    public static void main(String[] args) {
       Scanner input = new Scanner(System.in);
       int speed1 = input.nextInt();
       int speed2= input.nextInt();
       long count = 1;
       long miliseconds = input.nextInt();
       for(int time = 0; time < miliseconds; time++){
           count =(int) (count * speed1 * 0.5 + count * speed2 * 0.5);
       }
       System.out.println((int) (count % (Math.pow(10,9)+7)));
    }
}