TwoSumPlusFakeInput

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class TargetSum {
    static void fakeInput() {
        String test = "1 1 1 1 1\n"
        + "3";
        System.setIn(new ByteArrayInputStream(test.getBytes()));
    }
    public static void main(String[] args) throws IOException {
        fakeInput();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int[] numbers = Arrays.stream(br.readLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();
        int targetSum = Integer.parseInt(br.readLine());
        int result = solve(0, numbers, 0, targetSum);
        System.out.println(result);
    }

    static int solve(int index, int[] numbers, int current, int target) {
        //stop
        if (index == numbers.length) {
            if (current == target) {
                return 1;
            }
            return 0;
        }
        int count = 0;
        count += solve(index + 1, numbers, current + numbers[index], target);
        count += solve(index + 1, numbers, current - numbers[index], target);
        return count;
    }
}