XPath 1.0 closest preceding and/or ancestor node with an attribute in a XML Tree

Here are three XML-trees

(1)

<?xml version="1.0" encoding="UTF-8"?>
<content>
   <section id="1">
        <section id="2"/>
        <section id="3"/>
        <section id="9"/>
    </section>
    <section id="4">
        <section id="5">
            <section>
                <bookmark/> <!-- here's the bookmark-->
                <section id="6">
                    <section id="7">
                        <section id="8"/>
                    </section>
               </section>
            </section>
        </section>
    </section>
</content>

(2)

<?xml version="1.0" encoding="UTF-8"?>
<content>
    <section id="1"/>
    <section id="2">
        <section id="9">
            <section id="10">
                <section id="11"/>
            </section>            
        </section>
        <section>
            <section id="4">
                <section id="5"/>
            </section>            
        </section>
        <section/>
        <bookmark/> <!-- here's the bookmark-->
        <section id="6">
            <section id="7">
                <section id="8"/>
            </section>
        </section>
    </section>
</content>

The desired result is in both cases the id 5.

With XSLT 1.0 and XPath 1.0 I can either get the ancestor from (1)

<xsl:value-of select="//bookmark/ancestor::*[@id][1]/@id"/>

or the preceding node from (2)

<xsl:value-of select="//bookmark/preceding::*[@id][1]/@id"/>

How do I get the nearest ancestor or preceding node with an id from my bookmark?
I need a single xsl:value-of which matches both cases. Thanks.

EDIT:

The solution should also cover this structure. Desired id is still 5.

(3)

<?xml version="1.0" encoding="UTF-8"?>
<content>
   <section id="1">
        <section id="2"/>
        <section id="3"/>
        <section id="9"/>
    </section>
    <section id="4">
        <section>
            <section id="10"/>
            <section id="5"/>
            <section>
                <bookmark/> <!-- here's the bookmark-->
                <section id="6">
                    <section id="7">
                        <section id="8"/>
                    </section>
                </section>
            </section>
        </section>
    </section>
</content>