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

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 in = new Scanner(System.in);
        long a=in.nextLong(), b=in.nextLong(); 
        long t=in.nextLong(), base=(a+b)/2;
        
        long ans=power(base,t);
        ans%=((long)1e9+7);
        System.out.print(ans);
    }
    
    
    static long power(long base, long exp)
{
if(exp==0)
return 1;
else if(exp==1)
return base;

long root=power(base,exp/2);
root=root%((long)1e9+7);
if(exp%2==0)
return root*root;
else 
return ((root*root)%(((long)1e9+7)))*base;
}
}