|시간 제한||메모리 제한||제출||정답||맞힌 사람||정답 비율|
|3 초||512 MB||6||3||3||50.000%|
In the rectangular coordinate system every point with integer coordinates is called p-point. Any segment with different ends being p-points, parallel to one of the axis of coordinates, is called p-segment. Only closed segments (with end points belonging to the segment) are taken into consideration. A broken line built from k p-segments, in which every two consecutive ones are perpendicular, we call p-broken-line of degree k.
Write a program which:
Description of a p-point consists of two non-negative integers, being being coordinates x and y adequately of this p-point, separated by a single space, These numbers are from range [0….1,000,000,000] The first line of the standard input contains only the description of the p-point A. The second line contains only the description of the p-point B. The third line consists exactly of one non-negative integer n being the number of p-segments, 1 ≤ n ≤ 50. Each of next n lines consists of descriptions of exactly two p-points, separated by a single space. These are coordinates of the ends of one p-segment.
The first and the the only line of standrd output should contain either one number being minimum degree of p-broken-line connecting points A and B and not crossing any of given p-segments, or the word "BRAK", if a p-broken-line having above-mentioned properties does not exist.
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