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

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();
        int t = in.nextInt();
        in.close();
        
        int cells = 1;
        for(int i=0; i<t; i++) {
            cells = getNumberOfCells(a, b, cells);
        }
        int answer = (int)(cells%(Math.pow(10,9)+7));
        System.out.println(answer);
    }
    public static int getNumberOfCells(int a, int b, int cells) {
        return (int)(0.5*a*cells)+(int)(0.5*b*cells);
    }
}