学姐的学弟

<span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">学姐正在Do homework，但是她写着写着就开始想学弟，走神的她就开始在纸上画圈圈。这时学弟突然出现了，好奇的学弟问学姐在做什么，惊慌之下，学姐随口说想算一下这些圆覆盖的面积为多少。学弟顿时非常仰慕学姐，但是学姐突然意识到自己不会做，为了自己能给学弟留下好印象，她来求助你帮她算出来这些圆覆盖的面积。</span><br /> <span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">为了简化问题，我们假设所有圆的半径都为1。</span>

<span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">输入有多组数据。开头为一items整数</span><span class="MathJax_Preview" style="font-family:Arial;font-size:14.3999996185303px;line-height:26px;color:#888888;background-color:#FFFFFF;"></span><span id="MathJax-Span-1" class="math"><span id="MathJax-Span-2" class="mrow"><span id="MathJax-Span-3" class="mi">T</span><span id="MathJax-Span-4" class="mo">(</span><span id="MathJax-Span-5" class="mi">T</span><span id="MathJax-Span-6" class="mo">≤</span><span id="MathJax-Span-7" class="mn">10</span><span id="MathJax-Span-8" class="mo">)</span></span></span><span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">，表示数据组数，接下来T组输入，每组开头为一items整数</span><span class="MathJax_Preview" style="font-family:Arial;font-size:14.3999996185303px;line-height:26px;color:#888888;background-color:#FFFFFF;"></span><span id="MathJax-Span-9" class="math"><span id="MathJax-Span-10" class="mrow"><span id="MathJax-Span-11" class="mi">n</span><span id="MathJax-Span-12" class="mo">(</span><span id="MathJax-Span-13" class="mn">1</span><span id="MathJax-Span-14" class="mo">≤</span><span id="MathJax-Span-15" class="mi">n</span><span id="MathJax-Span-16" class="mo">≤</span><span id="MathJax-Span-17" class="mn">100</span><span id="MathJax-Span-18" class="mo">)</span></span></span><span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">，表示学姐画的圆的items数，接下来</span><span class="MathJax_Preview" style="font-family:Arial;font-size:14.3999996185303px;line-height:26px;color:#888888;background-color:#FFFFFF;"></span><span id="MathJax-Span-19" class="math"><span id="MathJax-Span-20" class="mrow">n</span></span><span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">行，每行两items整数</span><span class="MathJax_Preview" style="font-family:Arial;font-size:14.3999996185303px;line-height:26px;color:#888888;background-color:#FFFFFF;"></span><span id="MathJax-Span-22" class="math"><span id="MathJax-Span-23" class="mrow"><span id="MathJax-Span-24" class="msubsup"><span id="MathJax-Span-25" class="mi">x</span><span id="MathJax-Span-26" class="mi">i</span></span><span id="MathJax-Span-27" class="mo">,</span><span id="MathJax-Span-28" class="msubsup"><span id="MathJax-Span-29" class="mi">y</span><span id="MathJax-Span-30" class="mi">i</span></span></span></span><span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">，表示圆的圆心坐标，</span><span class="MathJax_Preview" style="font-family:Arial;font-size:14.3999996185303px;line-height:26px;color:#888888;background-color:#FFFFFF;"></span><span id="MathJax-Span-31" class="math"><span id="MathJax-Span-32" class="mrow"><span id="MathJax-Span-33" class="mn">1</span><span id="MathJax-Span-34" class="mo">≤</span><span id="MathJax-Span-35" class="msubsup"><span id="MathJax-Span-36" class="mi">x</span><span id="MathJax-Span-37" class="mi">i</span></span><span id="MathJax-Span-38" class="mo">,</span><span id="MathJax-Span-39" class="msubsup"><span id="MathJax-Span-40" class="mi">y</span><span id="MathJax-Span-41" class="mi">i</span></span><span id="MathJax-Span-42" class="mo">≤</span><span id="MathJax-Span-43" class="mn">100</span></span></span><span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">。</span>

<span style="color:#333333;font-family:Arial;font-size:14.3999996185303px;line-height:26px;background-color:#FFFFFF;">输出一items数，表示面积并，精确到小数点后五位。</span>