package barrels; import java.util.Scanner; public class Barrels { public static void main(String[] args) { // write your code here Scanner scanner = new Scanner(System.in); int num1 = scanner.nextInt(); int num2 = scanner.nextInt(); int length = scanner.nextInt(); int interested = scanner.nextInt(); if(interested != num1 && interested != num2) { System.out.println(0); return; } long res = 1; for (int i = 0; i < length; i++) { res = res * 2; res = res % 1000000007; } res = (res * length ) % 1000000007; res = res / 2; System.out.println(res); } }