1 <span class="kw3">rand</span><span class="br0">(</span><span class="st0">"10000000000000000"</span>.<span class="me1">to_i</span><span class="br0">(</span><span class="nu0">16</span><span class="br0">)</span><span class="br0">)</span>.<span class="me1">to_s</span><span class="br0">(</span><span class="nu0">16</span><span class="br0">)</span>.<span class="me1">upcase</span>