import java.math.BigInteger;
import java.util.Scanner;


public class Solution 
{	
	public static void main(String[]args)
	{
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int sum = (a + b) / 2;
		BigInteger t = sc.nextBigInteger();
		BigInteger cells = BigInteger.valueOf(sum);
		BigInteger x = BigInteger.valueOf(1000000007);
		cells = cells.modPow(t, x);
		System.out.print(cells);
	}
}