Codeforces 上的样例

3
4
0 -2
1 0
-1 0
0 2
3
0 2
-3 0
0 -1
1
0 0

然而洛谷样例

<div class="test-example-line test-example-line-even test-example-line-0">3</div><div class="test-example-line test-example-line-odd test-example-line-1">4</div><div class="test-example-line test-example-line-odd test-example-line-1">0 -2</div><div class="test-example-line test-example-line-odd test-example-line-1">1 0</div><div class="test-example-line test-example-line-odd test-example-line-1">-1 0</div><div class="test-example-line test-example-line-odd test-example-line-1">0 2</div><div class="test-example-line test-example-line-even test-example-line-2">3</div><div class="test-example-line test-example-line-even test-example-line-2">0 2</div><div class="test-example-line test-example-line-even test-example-line-2">-3 0</div><div class="test-example-line test-example-line-even test-example-line-2">0 -1</div><div class="test-example-line test-example-line-odd test-example-line-3">1</div><div class="test-example-line test-example-line-odd test-example-line-3">0 0</div><div class="test-example-line test-example-line-odd test-example-line-3"></div>

不知道为什么带了一堆 HTML