Dominoes

题意翻译

给定 $n$ 和 $n$ 个二元组 $(a_i,b_i)$ 。 你可以任意排列这几个二元组，也可以任意更换一个二元组之间的两个元素的顺序。 是否存在一种解，使得任意相邻的两个二元组中，相邻的两个元素相等。 输出其排列顺序，并输出其是否需要改变两个元素的顺序(``+``/``-``)。 By [Error_Eric](https://www.luogu.com.cn/user/217300) .

题目描述

You have a set of dominoes. Each domino is a rectangular tile with a line dividing its face into two square ends. Can you put all dominoes in a line one by one from left to right so that any two dominoes touched with the sides that had the same number of points? You can rotate the dominoes, changing the left and the right side (domino "1-4" turns into "4-1").

输入输出格式

输入格式

The first line contains number $ n $ ( $ 1<=n<=100 $ ). Next $ n $ lines contains the dominoes. Each of these lines contains two numbers — the number of points (spots) on the left and the right half, correspondingly. The numbers of points (spots) are non-negative integers from 0 to 6.

输出格式

Print "No solution", if it is impossible to arrange the dominoes in the required manner. If the solution exists, then describe any way to arrange the dominoes. You put the dominoes from left to right. In each of $ n $ lines print the index of the domino to put in the corresponding position and then, after a space, character "+" (if you don't need to turn the domino) or "–" (if you need to turn it).

输入输出样例

输入样例 #1

5
1 2
2 4
2 4
6 4
2 1

输出样例 #1

2 -
1 -
5 -
3 +
4 -