Codeforces Round 133 (Div. 2)
D
Spider's Web
Codeforces
1700
原题
← CE →
翻译中…

Paw the Spider is making a web. Web-making is a real art, Paw has been learning to do it his whole life. Let's consider the structure of the web.

翻译中…

image

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There are $*n*$ main threads going from the center of the web. All main threads are located in one plane and divide it into $*n*$ equal infinite sectors. The sectors are indexed from $1$ to $*n*$ in the clockwise direction. Sectors $*i*$ and $*i* + 1$ are adjacent for every $*i*$, $1 ≤ *i* < *n*$. In addition, sectors $1$ and $*n*$ are also adjacent.

翻译中…

Some sectors have bridge threads. Each bridge connects the two main threads that make up this sector. The points at which the bridge is attached to the main threads will be called attachment points. Both attachment points of a bridge are at the same distance from the center of the web. At each attachment point exactly one bridge is attached. The bridges are adjacent if they are in the same sector, and there are no other bridges between them.

翻译中…

A cell of the web is a trapezoid, which is located in one of the sectors and is bounded by two main threads and two adjacent bridges. You can see that the sides of the cell may have the attachment points of bridges from adjacent sectors. If the number of attachment points on one side of the cell is not equal to the number of attachment points on the other side, it creates an imbalance of pulling forces on this cell and this may eventually destroy the entire web. We'll call such a cell unstable. The perfect web does not contain unstable cells.

翻译中…

Unstable cells are marked red in the figure. Stable cells are marked green.

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Paw the Spider isn't a skillful webmaker yet, he is only learning to make perfect webs. Help Paw to determine the number of unstable cells in the web he has just spun.

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Input

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The first line contains integer $*n*$ ($3 ≤ *n* ≤ 1000$) — the number of main threads.

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The $*i*$-th of following $*n*$ lines describe the bridges located in the $*i*$-th sector: first it contains integer $*k*_{*i*}$ ($1 ≤ *k*_{*i*} ≤ 10^{5}$) equal to the number of bridges in the given sector. Then follow $*k*_{*i*}$ different integers $*p*_{*ij*}$ ($1 ≤ *p*_{*ij*} ≤ 10^{5}; 1 ≤ *j* ≤ *k*_{*i*}$). Number $*p*_{*ij*}$ equals the distance from the attachment points of the $*j*$-th bridge of the $*i*$-th sector to the center of the web.

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It is guaranteed that any two bridges between adjacent sectors are attached at a different distance from the center of the web. It is guaranteed that the total number of the bridges doesn't exceed $10^{5}$.

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Output

翻译中…

Print a single integer — the number of unstable cells in Paw the Spider's web.

翻译中…

样例

Input #1
7
3 1 6 7
4 3 5 2 9
2 8 1
4 3 7 6 4
3 2 5 9
3 6 3 8
3 4 2 9
Output #1
6
InputCopy OutputCopy
题目信息
题号
216D
时间限制
2 s
内存限制
256 MB
标签
二分
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题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。