import java.io.*;
import java.util.*;
import java.math.BigDecimal;
import java.math.BigInteger;

public class Solution {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int a = s.nextInt(), b = s.nextInt();
        long t = s.nextLong();
        
        BigInteger result = BigInteger.ONE, TWO = BigInteger.valueOf(2), a_ = BigInteger.valueOf(a), b_ = BigInteger.valueOf(b);
        
        //(0.5 * (a + b)) ^ t mod 1000000007
        /*for(long i = 0; i < t; i++) {
            BigInteger A = result.multiply(a_), B = result.multiply(b_);
            result = A.add(B).divide(TWO);
        }*/
        
        result = a_.add(b_).divide(TWO).modPow(BigInteger.valueOf(t), BigInteger.valueOf(1000000000 + 7));
        
        System.out.println(result);
    }
}