Description
Input
First line, you will get the row and column of the matrix.
1 <= R <= 105, 1 <= C <= 105
Second line, you will get the start position of the matrix.
0 <= X < 105, 0 <= Y < 105
Third line, you will get a 2D matrix, for each element N in the matrix:
-1 <= N <= 9
Output
The output should be the distance from root to leaf of the shortest path.
(Remember to print out "\n" after the answer)