CF995C.Leaving the Bar

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题目描述

For a vector v=(x,y)\vec{v} = (x, y) , define v=x2+y2|v| = \sqrt{x^2 + y^2} .

Allen had a bit too much to drink at the bar, which is at the origin. There are nn vectors v1,v2,,vn\vec{v_1}, \vec{v_2}, \cdots, \vec{v_n} . Allen will make nn moves. As Allen's sense of direction is impaired, during the ii -th move he will either move in the direction vi\vec{v_i} or vi-\vec{v_i} . In other words, if his position is currently p=(x,y)p = (x, y) , he will either move to p+vip + \vec{v_i} or pvip - \vec{v_i} .

Allen doesn't want to wander too far from home (which happens to also be the bar). You need to help him figure out a sequence of moves (a sequence of signs for the vectors) such that his final position pp satisfies p1.5106|p| \le 1.5 \cdot 10^6 so that he can stay safe.

输入格式

The first line contains a single integer nn ( 1n1051 \le n \le 10^5 ) — the number of moves.

Each of the following lines contains two space-separated integers xix_i and yiy_i , meaning that vi=(xi,yi)\vec{v_i} = (x_i, y_i) . We have that vi106|v_i| \le 10^6 for all ii .

输出格式

Output a single line containing nn integers c1,c2,,cnc_1, c_2, \cdots, c_n , each of which is either 11 or 1-1 . Your solution is correct if the value of p=i=1ncivip = \sum_{i = 1}^n c_i \vec{v_i} , satisfies p1.5106|p| \le 1.5 \cdot 10^6 .

It can be shown that a solution always exists under the given constraints.

输入输出样例

  • 输入#1

    3
    999999 0
    0 999999
    999999 0
    

    输出#1

    1 1 -1 
    
  • 输入#2

    1
    -824590 246031
    

    输出#2

    1 
    
  • 输入#3

    8
    -67761 603277
    640586 -396671
    46147 -122580
    569609 -2112
    400 914208
    131792 309779
    -850150 -486293
    5272 721899
    

    输出#3

    1 1 1 1 1 1 1 -1 
    
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