Canadian Computing Competition: 2008 Stage 1, Senior #3

In order to make a few dollars, you have decided to become part of a scientific experiment. You are fed lots of pizza, then more pizza and then you are asked to find your way across the city on a scooter powered only by pizza. Of course, the city has lots of intersections, and these intersections are very controlled. Some intersections are forbidden for you to enter; some only let you move north/south as you leave the intersection; others let you move only east/west as you leave the intersection; and the rest let you go in any compass direction (north, south, east or west).

Thankfully your scientific friends have given you a map of the city (on the back of a pizza box), with an arrangement of symbols indicating how you can move around the city. Specifically, there are 4 different symbols on the box:

• The symbol + indicates we can move in any direction (north/south/east/west) from this location.
• The symbol - indicates we can move only east or west from this location.
• The symbol | indicates we can move only north or south from this location.
• The symbol * indicates we cannot occupy this location.

Your task is to determine how many intersections you must pass through to move from the north-west corner of the city to the south-east corner of the city.

Input Specification

The input begins with a number \(t\) \((1 \le t \le 10)\) on its own line, which indicates how many different cases are contained in this file. Each case begins with a number \(r\) on one line, followed by a number \(c\) on the next line \((1 \le r, c \le 20)\) . The next \(r\) lines contain \(c\) characters, where each character is one of { + , * , - , | }. You may assume the north-west corner of the city can be occupied (i.e., it will not be marked with * ).

Output Specification

The output will be \(t\) lines long, with one integer per line. The integer on line \(i\) \((1 \le i \le t)\) indicates the minimum number of intersections required to pass through as you move from the north-west corner of the city to the south-east corner of the city. If there is no way to get from the north-west corner to the south-east corner, output -1 for that test case.

Sample Input

3
2
2
-|
*+
3
5
+||*+
+++|+
**--+
2
3
+*+
+*+

Output for Sample Input

3
7
-1