著名的王牌间谍 007 需要执行一次任务,获取敌方的机密情报。已知情报藏在一个地下迷宫里,迷宫只有一个入口,里面有很多条通路,每条路通向一扇门。每一扇门背后或者是一个房间,或者又有很多条路,同样是每条路通向一扇门…… 他的手里有一张表格,是其他间谍帮他收集到的情报,他们记下了每扇门的编号,以及这扇门背后的每一条通路所到达的门的编号。007 发现不存在两条路通向同一扇门。
内线告诉他,情报就藏在迷宫的最深处。但是这个迷宫太大了,他需要你的帮助 —— 请编程帮他找出距离入口最远的那扇门。
输入首先在一行中给出正整数 N(<105),是门的数量。最后 N 行,第 i 行(1≤i≤N)按以下格式描述编号为 i 的那扇门背后能通向的门:
其中K是通道的数量,其后是每扇门的编号。
在一行中输出距离入口最远的那扇门的编号。题目保证这样的结果是唯一的。
输入格式:
K D[1] D[2] ... D[K]
输出格式:
输入样例:
13
3 2 3 4
2 5 6
1 7
1 8
1 9
0
2 11 10
1 13
0
0
1 12
0
0
输出样例:
12
Input consists of several test cases. For each case, a sequence of coordinates is given. Each pair of x and y occupies a line, with |x| and |y| less than 2^31. The sequence is terminated with a pair of 0's. Note that (0, 0) will never be considered as a point on any of the polygonal lines. An empty polygonal line signals the end of input.
For each test case, print in one line two pairs of numbers, which are the south-west and north-east corners of the surrounding rectangle. The numbers must be separated by one space as is indicated in the samples.
12 56
23 56
13 10
0 0
12 34
0 0
0 0
12 10 23 56
12 34 12 34