import org.jetbrains.annotations.NotNull;

class JavaClass {
    @NotNull JavaClass plus(Runnable i) {
        i.run();
        return this;
    }

    @NotNull JavaClass minus(Runnable i) {
        i.run();
        return this;
    }

    @NotNull JavaClass times(Runnable i) {
        i.run();
        return this;
    }

    @NotNull JavaClass div(Runnable i) {
        i.run();
        return this;
    }

    @NotNull JavaClass mod(Runnable i) {
        i.run();
        return this;
    }
}