description: The robot is located on a checkered rectangular board of size n × m (n rows, m columns). The rows in the board are numbered from 1 to n from top to bottom, and the columns — from 1 to m from left to right.
  
  The robot is able to move from the current cell to one of the four cells adjacent by side.
  
  Each cell has one of the symbols 'L', 'R', 'D' or 'U' written on it, indicating the direction in which the robot will move when it gets in that cell — left, right, down or up, respectively.
  
  The robot can start its movement in any cell. He then moves to the adjacent square in the direction indicated on the current square in one move. 
  
    * If the robot moves beyond the edge of the board, it falls and breaks. 
    * If the robot appears in the cell it already visited before, it breaks (it stops and doesn't move anymore). 
  
  
  
  Robot can choose any cell as the starting cell. Its goal is to make the maximum number of steps before it breaks or stops.
  
  Determine from which square the robot should start its movement in order to execute as many commands as possible. A command is considered successfully completed if the robot has moved from the square on which that command was written (it does not matter whether to another square or beyond the edge of the board).
  
  Input
  
  The first line contains an integer t (1 ≤ t ≤ 10000) — the number of test cases in the test.
  
  Each test case's description is preceded by a blank line. Next is a line that contains integers n and m (1 ≤ n ≤ 2000; 1 ≤ m ≤ 2000) — the height and width of the board. This line followed by n lines, the i-th of which describes the i-th line of the board. Each of them is exactly m letters long and consists of symbols 'L', 'R', 'D' and 'U'.
  
  It is guaranteed that the sum of sizes of all boards in the input does not exceed 4⋅10^6.
  
  Output
  
  For each test case, output three integers r, c and d (1 ≤ r ≤ n; 1 ≤ c ≤ m; d ≥ 0), which denote that the robot should start moving from cell (r, c) to make the maximum number of moves d. If there are several answers, output any of them.
  
  Example
  
  Input
  
  
  7
  
  1 1
  R
  
  1 3
  RRL
  
  2 2
  DL
  RU
  
  2 2
  UD
  RU
  
  3 2
  DL
  UL
  RU
  
  4 4
  RRRD
  RUUD
  URUD
  ULLR
  
  4 4
  DDLU
  RDDU
  UUUU
  RDLD
  
  
  Output
  
  
  1 1 1
  1 1 3
  1 1 4
  2 1 3
  3 1 5
  4 3 12
  1 1 4
solution: import java.io.*;
  import java.util.*;
  
  
  public class Practice
  {
  //	static final long mod=7420738134811L;
  	static int mod=1000000007;
  	static final int size=501;
  	static FastReader sc=new FastReader(System.in);
  //	static Reader sc=new Reader();
  	static  PrintWriter out=new PrintWriter(System.out);
  	static long[] factorialNumInverse;
  	static long[] naturalNumInverse;	
  	static int[] sp;
  	static long[] fact;
  	static ArrayList<Integer> pr;
  	public static void main(String[] args) throws IOException
  	{
  //		System.setIn(new FileInputStream("input.txt"));
  //		System.setOut(new PrintStream("output.txt"));
  //		factorial(mod);
  //		InverseofNumber(mod);
  //		InverseofFactorial(mod);
  //		make_seive();
  		int t=1;
  		t=sc.nextInt();
  		while(t-->0)
  			solve();
  		out.close();
  		out.flush();
  	}
  	static void solve() throws IOException
  	{
  		int n=sc.nextInt(),m=sc.nextInt();
  		char a[][]=new char[n][m];
  		for(int i=0;i<n;i++)
  			a[i]=sc.next().toCharArray();
  		int dis[][]=new int[n][m];
  		for(int i=0;i<n;i++)
  		for(int j=0;j<m;j++)
  		if(dis[i][j]==0)
  		{
  			int ii=i,jj=j;
  			int d=0;
  			while(i>=0 && i<n && j>=0 && j<m && dis[i][j]==0)
  			{
  				d++;
  				dis[i][j]=-1;
  				if(a[i][j]=='U')
  					i--;
  				else if(a[i][j]=='D')
  					i++;
  				else if(a[i][j]=='R')
  					j++;
  				else
  					j--;
  			}
  			if(i<0 || i>=n || j<0 || j>=m)
  				d+=0;
  			else if(dis[i][j]!=-1)
  				d+=dis[i][j];
  			else
  			{
  				int c=0;
  				while(i>=0 && i<n && j>=0 && j<m && dis[i][j]==-1)
  				{
  					c++;
  					dis[i][j]=-2;
  					if(a[i][j]=='U')
  						i--;
  					else if(a[i][j]=='D')
  						i++;
  					else if(a[i][j]=='R')
  						j++;
  					else
  						j--;
  				}
  				while(i>=0 && i<n && j>=0 && j<m && dis[i][j]==-2)
  				{
  					dis[i][j]=c;
  					if(a[i][j]=='U')
  						i--;
  					else if(a[i][j]=='D')
  						i++;
  					else if(a[i][j]=='R')
  						j++;
  					else
  						j--;
  				}
  			}
  			i=ii;j=jj;
  			while(i>=0 && i<n && j>=0 && j<m && dis[i][j]==-1)
  			{
  				dis[i][j]=d--;
  				if(a[i][j]=='U')
  					i--;
  				else if(a[i][j]=='D')
  					i++;
  				else if(a[i][j]=='R')
  					j++;
  				else
  					j--;
  			}
  			i=ii;j=jj;
  		}
  		int ai=-1,aj=-1;
  		for(int i=0;i<n;i++)
  			for(int j=0;j<m;j++)
  			{
  				if(ai==-1 && aj==-1 || dis[ai][aj]<dis[i][j])
  				{
  					ai=i;aj=j;
  				}
  			}
  		ai++;
  		aj++;
  		out.println(ai+" "+aj+" "+dis[ai-1][aj-1]);
  	}
  	static class Pair implements Cloneable, Comparable<Pair>
  	{
  		int x,y;
  		Pair(int a,int b)
  		{
  			this.x=a;
  			this.y=b;
  		}
  		@Override
  		public boolean equals(Object obj) 
  		{
  			if(obj instanceof  Pair)
  			{
  				Pair p=(Pair)obj;
  				return p.x==this.x && p.y==this.y;
  			}
  			return false;
  		}
  		@Override
  		public int hashCode() 
  		{
  			return Math.abs(x)+500*Math.abs(y);
  		}
  		@Override
  		public String toString() 
  		{
  			return "("+x+" "+y+")";
  		}
  		@Override
  		protected Pair clone() throws CloneNotSupportedException {
  			return new Pair(this.x,this.y);
  		}
  		@Override
  		public int compareTo(Pair a) 
  		{
  			int t= this.x-a.x;
  			if(t!=0)
  				return t;
  			else
  				return this.y-a.y;
  		}
  		public void swap()
  		{
  			this.y=this.y+this.x;
  			this.x=this.y-this.x;
  			this.y=this.y-this.x;			
  		}
  	}
  	static class Tuple implements Cloneable, Comparable<Tuple>
  	{
  		int x,y,z;
  		Tuple(int a,int b,int c)
  		{
  			this.x=a;
  			this.y=b;
  			this.z=c;
  		}
  		public boolean equals(Object obj) 
  		{
  			if(obj instanceof  Tuple)
  			{
  				Tuple p=(Tuple)obj;
  				return p.x==this.x && p.y==this.y && p.z==this.z;
  			}
  			return false;
  		}
  		@Override
  		public int hashCode() 
  		{
  			return (this.x+501*this.y);
  		}
  		@Override
  		public String toString() 
  		{
  			return "("+x+","+y+","+z+")";
  		}
  		@Override
  		protected Tuple clone() throws CloneNotSupportedException {
  			return new Tuple(this.x,this.y,this.z);
  		}
  		@Override
  		public int compareTo(Tuple a) 
  		{
  			int x=this.z-a.z;
  			if(x!=0)
  				return x;
  			int X= this.x-a.x;
  			if(X!=0)
  				return X;
  			return a.y-this.y;
  		}
  	}
  	static void arraySort(int arr[])
  	{
  		ArrayList<Integer> a=new ArrayList<Integer>();
  		for (int i = 0; i < arr.length; i++) {
  			a.add(arr[i]);
  		}
  		Collections.sort(a);
  		for (int i = 0; i < arr.length; i++) {
  			arr[i]=a.get(i);
  		}
  	}
  	static void arraySort(long arr[])
  	{
  		ArrayList<Long> a=new ArrayList<Long>();
  		for (int i = 0; i < arr.length; i++) {
  			a.add(arr[i]);
  		}
  		Collections.sort(a);
  		for (int i = 0; i < arr.length; i++) {
  			arr[i]=a.get(i);
  		}
  	}
  	static HashSet<Integer> primeFactors(int n)
  	{
  		HashSet<Integer> ans=new HashSet<Integer>();
  		if(n%2==0)
  		{
  			ans.add(2);
  			while((n&1)==0)
  				n=n>>1;
  		}
  		for(int i=3;i*i<=n;i+=2)
  		{
  			if(n%i==0)
  			{
  				ans.add(i);
  				while(n%i==0)
  					n=n/i;
  			}
  		}
  		if(n!=1)
  			ans.add(n);
  		return ans;
  	}
  	static void make_seive()
  	{
  		sp=new int[size];
  		pr=new ArrayList<Integer>();
  		for (int i=2; i<size; ++i) {
  		    if (sp[i] == 0) {
  		        sp[i] = i;
  		        pr.add(i);
  		    }
  		    for (int j=0; j<(int)pr.size() && pr.get(j)<=sp[i] && i*pr.get(j)<size; ++j)
  		        sp[i * pr.get(j)] = pr.get(j);
  		}
  	}
  	public static void InverseofNumber(int p)
  	{
  		naturalNumInverse=new long[size];
  	    naturalNumInverse[0] = naturalNumInverse[1] = 1;
  	    for(int i = 2; i < size; i++)
  	        naturalNumInverse[i] = naturalNumInverse[p % i] * (long)(p - p / i) % p;
  	}
  	// Function to precompute inverse of factorials
  	public static void InverseofFactorial(int p)
  	{
  		factorialNumInverse=new long[size];
  	    factorialNumInverse[0] = factorialNumInverse[1] = 1;
  	    // pre-compute inverse of natural numbers
  	    for(int i = 2; i < size; i++)
  	        factorialNumInverse[i] = (naturalNumInverse[i] * factorialNumInverse[i - 1]) % p;
  	}
  	// Function to calculate factorial of 1 to 200001
  	public static void factorial(int p)
  	{
  		fact=new long[size];
  	    fact[0] = 1;
  	    for(int i = 1; i < size; i++)
  	        fact[i] = (fact[i - 1] * (long)i) % p;
  	}
  	 
  	// Function to return nCr % p in O(1) time
  	public static long Binomial(int N, int R)
  	{
  		if(R<0)
  			return 1;
  	    // n C r = n!*inverse(r!)*inverse((n-r)!)
  	    long ans = ((fact[N] * factorialNumInverse[R]) % mod * factorialNumInverse[N - R]) % mod;
  	    return ans;
  	}
  	static int findXOR(int x)	//from 0 to x
  	{
  		if(x<0)
  			return 0;
  		if(x%4==0)
  			return x;
  		if(x%4==1)
  			return 1;
  		if(x%4==2)
  			return x+1;
  		return 0;
  	}
  	static boolean isPrime(long x)
  	{
  		if(x==1)
  			return false;
  		if(x<=3)
  			return true;
  		if(x%2==0 || x%3==0)
  			return false;
  		for(int i=5;i<=Math.sqrt(x);i+=2)
  			if(x%i==0)
  				return false;
  		return true;
  	}
  	static long gcd(long a,long b)
  	{
  		return (b==0)?a:gcd(b,a%b);
  	}
  	static int gcd(int a,int b)
  	{
  		return (b==0)?a:gcd(b,a%b);
  	}
  	static class Node
  	{
  		int vertex;
  		HashSet<Edge> adj;
  		int taxC,taxD;
  		Node(int ver)
  		{
  			vertex=ver;
  			taxD=0;
  			taxC=0;
  			adj=new HashSet<Edge>();
  		}
  		@Override
  		public String toString() 
  		{
  			return vertex+" ";
  		}
  	}
  	static class Edge
  	{
  		Node to;
  		int cost;
  		Edge(Node t,int c)
  		{
  			this.to=t;
  			this.cost=c;
  		}
  		@Override
  		public String toString() {
  			return "("+to.vertex+","+cost+") ";
  		}
  	}
  	static long power(long x, long y)
  	  {
  		if(x<=0)
  			return 1;
  	    long res = 1; 
  	    x = x % mod; 
  	    if (x == 0)
  	      return 0; 
  	    while (y > 0)
  	    {
  	    	if ((y & 1) != 0)
  	    		res = (res * x) % mod;
  	    	
  	    	y = y >> 1; // y = y/2
  	    	x = (x * x) % mod;
  	    }
  	    return res;
  	  }
  	static long binomialCoeff(long n, long k)
      {
  		if(n<k)
  			return 0;
          long res = 1;
  //        if(k>n)
  //        	return 0;
          // Since C(n, k) = C(n, n-k)
          if (k > n - k)
              k = n - k;
   
          // Calculate value of
          // [n * (n-1) *---* (n-k+1)] / [k * (k-1) *----* 1]
          for (long i = 0; i < k; ++i) {
              res *= (n - i);
              res /= (i + 1);
          }
   
          return res;
      }
  	static class FastReader
  	{
          byte[] buf = new byte[2048];
          int index, total;
          InputStream in;
   
          FastReader(InputStream is) 
          {
              in = is;
          }
   
          int scan() throws IOException 
          {
              if (index >= total) {
                  index = 0;
                  total = in.read(buf);
                  if (total <= 0) {
                      return -1;
                  }
              }
              return buf[index++];
          }
   
          String next() throws IOException 
          {
              int c;
              for (c = scan(); c <= 32; c = scan());
              StringBuilder sb = new StringBuilder();
              for (; c > 32; c = scan()) {
                  sb.append((char) c);
              }
              return sb.toString();
          }
   
          int nextInt() throws IOException 
          {
              int c, val = 0;
              for (c = scan(); c <= 32; c = scan());
              boolean neg = c == '-';
              if (c == '-' || c == '+') {
                  c = scan();
              }
              for (; c >= '0' && c <= '9'; c = scan()) {
                  val = (val << 3) + (val << 1) + (c & 15);
              }
              return neg ? -val : val;
          }
   
          long nextLong() throws IOException 
          {
              int c;
              long val = 0;
              for (c = scan(); c <= 32; c = scan());
              boolean neg = c == '-';
              if (c == '-' || c == '+') {
                  c = scan();
              }
              for (; c >= '0' && c <= '9'; c = scan()) {
                  val = (val << 3) + (val << 1) + (c & 15);
              }
              return neg ? -val : val;
          }
      }
  	static class Reader 
  	{
          final private int BUFFER_SIZE = 1 << 16;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
   
          public Reader()
          {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public Reader(String file_name) throws IOException
          {
              din = new DataInputStream(
                  new FileInputStream(file_name));
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public String readLine() throws IOException
          {
              byte[] buf = new byte[64]; // line length
              int cnt = 0, c;
              while ((c = read()) != -1) {
                  if (c == '\n') {
                      if (cnt != 0) {
                          break;
                      }
                      else {
                          continue;
                      }
                  }
                  buf[cnt++] = (byte)c;
              }
              return new String(buf, 0, cnt);
          }
   
          public int nextInt() throws IOException
          {
              int ret = 0;
              byte c = read();
              while (c <= ' ') {
                  c = read();
              }
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          public long nextLong() throws IOException
          {
              long ret = 0;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg)
                  return -ret;
              return ret;
          }
   
          public double nextDouble() throws IOException
          {
              double ret = 0, div = 1;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
   
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (c == '.') {
                  while ((c = read()) >= '0' && c <= '9') {
                      ret += (c - '0') / (div *= 10);
                  }
              }
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          private void fillBuffer() throws IOException
          {
              bytesRead = din.read(buffer, bufferPointer = 0,
                                   BUFFER_SIZE);
              if (bytesRead == -1)
                  buffer[0] = -1;
          }
   
          private byte read() throws IOException
          {
              if (bufferPointer == bytesRead)
                  fillBuffer();
              return buffer[bufferPointer++];
          }
   
          public void close() throws IOException
          {
              if (din == null)
                  return;
              din.close();
          }
          public void printarray(int arr[])
          {
          	for (int i = 0; i < arr.length; i++)
  				System.out.print(arr[i]+" ");
          	System.out.println();
          }
      }
  }
  
  
  
  
  
  
  
  