import java.util.Scanner;

public class Barrels {

    public static void main(String[] args) {
        int a,b,c,k;
        Scanner sken = new Scanner(System.in);
        a = sken.nextInt();
        b = sken.nextInt();
        k = sken.nextInt();
        c = sken.nextInt();

        int vysledok = (int) (((Math.pow(2,k)*k)/2)%1000000007);
        System.out.println(vysledok);
    }
}