Problem Statement

You are given a A*B character matrix named C. Every cell in C has a character U,R,L or D indicating up,right,left and down.*

Your target is to go from top left corner to the bottom right corner of the matrix. But there are some restrictions while moving along the matrix: • If you follow what is written in the cell then you can move freely. • But if you don't follow what is written in the cell then you have to pay 1 unit of cost. Like: If a cell contains character U and you go right instead of Up you have to pay 1 unit of cost. So your task is to find the minimum cost to go from top-left corner to the bottom-right corner.

Problem Constraints

• 1 <= A,B <= 103 • C[i][j] can be either U,R,L or D.

Input Format

• First Argument represents a integer A (number of rows). • Second Argument represents a integer B (number of columns). • Third Argument represents a string array C which contains A strings each of length B.

Output Format

Return an integer denoting the minimum cost to travel from top-left corner to bottom-right corner.

Example Input

*Input:1

A = 3 B = 3 C = ["RRR","DDD","UUU"]

Input:2

A = 1 B = 4 C = ["LLLL"]*

Example Output

*Output-1 : 1 Output-2 : 3

Example Explanation*

Explanation for Input-1:

 Matrix looks like:RRR
                    DDD
                    UUU
 We go right two times and down two times.
 So from top-right cell we are going down though right is given so this incurs a cost of 1.

Explanation for Input-2:

 Matrix looks like:LLLL
 We go right three times.

Problem Link

Min Cost Path - InterviewBit