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

public class Solution {

    static long t = 1;
    static int a = 2;
    static int b = 4;
    static long noOfVirus = 1;
    
    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = readLine(br);
        String[] lineParts = line.split(" ");
        a = Integer.parseInt(lineParts[0]);
        b = Integer.parseInt(lineParts[1]);
        t = Long.parseLong(lineParts[2]);
        
        for(long i = 1; i <= t; i++)
            noOfVirus = ((a * noOfVirus + b * noOfVirus) / 2) % (1000000007);
           
        System.out.println(noOfVirus);
    }
    
    private static String readLine(BufferedReader br)
    {
        String line = "";
        try{
            line = br.readLine();
        } catch(Exception e){}
        
        return line.trim();
    }
}