public class Main {
 
    private static boolean func(boolean a, boolean b, boolean c, boolean d) {
        return ((a != b) & (c != d)) | ((b != c) & (a != d));
    }
 
    private static boolean testFunc(boolean a, boolean b, boolean c, boolean d) {
        int tmp = 0;
        tmp += a ? 1 : 0;
        tmp += b ? 1 : 0;
        tmp += c ? 1 : 0;
        tmp += d ? 1 : 0;
        return tmp == 2;
    }
 
    public static void main(String[] args) {
        for (int i = 0; i < 15; i++) {
            boolean a = ((i & 1) == 1);
            boolean b = ((i & 2) == 2);
            boolean c = ((i & 4) == 4);
            boolean d = ((i & 8) == 8);
            System.out.println(i + ": func(" + a + ", " + b + ", " + c + ", " + d + ") = " + testFunc(a, b, c, d) + " | " +
                    func(a, b, c, d));
        }
    }
}

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