Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

<image>

In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;
import java.util.Map.Entry;
import java.lang.Math;
import java.math.BigInteger;

public class Problem {
	class Pair implements Comparable<Pair>{
		int from, to;
		Pair(int from, int to){
			this.to= to;
			this.from = from;
		}
		@Override
		public int compareTo(Pair o) {
			return Integer.compare(this.to, o.to);
		}
	}

	List<Integer>[] graph;
	boolean[] used;
	int counter = 0;
	ArrayList<Integer>[] ansList;

	void solve() throws IOException {
		int n = rI();
		int m = rI();
		
		int[][] matr = new int[n][m];
		ArrayList<String> ansList = new ArrayList<>();
		for(int i=0;i<n;++i){
			for(int j=0;j<m;++j){
				matr[i][j] = rI();
			}
		}
		
		if(n<m){
			for(int i=0;i<n;++i){
				int min = Integer.MAX_VALUE;
				for(int j=0;j<m;++j){
					min = Math.min(min, matr[i][j]);
				}
				String curAns = "row "+(i+1);
				for(int j=0;j<min;++j){
					ansList.add(curAns);
				}
				for(int j=0;j<m;++j){
					matr[i][j]-=min;
				}
			}
			
			for(int i=0;i<m;++i){
				int min = Integer.MAX_VALUE;
				for(int j=0;j<n;++j){
					min = Math.min(min, matr[j][i]);
				}
				String curAns = "col "+(i+1);
				for(int j=0;j<min;++j){
					ansList.add(curAns);
				}
				for(int j=0;j<n;++j){
					matr[j][i]-=min;
				}
			}
			
			for(int i=0;i<n;++i){
				for(int j=0;j<m;++j){
					if(matr[i][j]!=0){
						out.println(-1);return;
					}
				}
			}
			out.println(ansList.size());
			for(String ans: ansList){
				out.println(ans);
			}
		}else{
			for(int i=0;i<m;++i){
				int min = Integer.MAX_VALUE;
				for(int j=0;j<n;++j){
					min = Math.min(min, matr[j][i]);
				}
				String curAns = "col "+(i+1);
				for(int j=0;j<min;++j){
					ansList.add(curAns);
				}
				for(int j=0;j<n;++j){
					matr[j][i]-=min;
				}
			}
			
			for(int i=0;i<n;++i){
				int min = Integer.MAX_VALUE;
				for(int j=0;j<m;++j){
					min = Math.min(min, matr[i][j]);
				}
				String curAns = "row "+(i+1);
				for(int j=0;j<min;++j){
					ansList.add(curAns);
				}
				for(int j=0;j<m;++j){
					matr[i][j]-=min;
				}
			}
			
			
			
			for(int i=0;i<n;++i){
				for(int j=0;j<m;++j){
					if(matr[i][j]!=0){
						out.println(-1);return;
					}
				}
			}
			out.println(ansList.size());
			for(String ans: ansList){
				out.println(ans);
			}
		}
		
		
	}

	int countPow(long n, int f) {
		int count = 0;
		while (n % f == 0) {
			count++;
			n /= f;
		}
		return count;
	}

	int checkBit(int mask, int bit) {
		return (mask >> bit) & 1;
	}

	public static void main(String[] args) throws IOException {

		new Problem().run();
	}

	boolean isLower(char a) {
		return ((int) a) >= 97 ? true : false;
	}

	long INF = Integer.MAX_VALUE - 12345;

	int[][] STEPS = { { 0, 1 }, { 1, 0 }, { -1, 0 }, { 0, -1 } };

	BufferedReader in;
	PrintWriter out;
	StringTokenizer tok;
	Random rnd = new Random();
	static final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;

	Problem() throws FileNotFoundException {

		if (ONLINE_JUDGE) {
			in = new BufferedReader(new InputStreamReader(System.in));
			out = new PrintWriter(System.out);
		} else {
			in = new BufferedReader(new FileReader("input.txt"));
			out = new PrintWriter("output.txt");
		}
		tok = new StringTokenizer("");
	}

	long checkBit(long mask, int bit) {
		return (mask >> bit) & 1;
	}

	// ======================================================

	// ======================================================
	void run() throws IOException {
		solve();
		out.close();
	}

	char[] reverseCharArray(char[] arr) {
		char[] ans = new char[arr.length];
		for (int i = 0; i < arr.length; ++i) {
			ans[i] = arr[arr.length - i - 1];
		}
		return ans;
	}

	int sqrt(double m) {
		int l = 0;
		int r = 1000000000 + 9;
		int i = 1000;
		while (r - l > 1) {
			int mid = (r + l) / 2;
			if (mid * mid > m) {
				r = mid;
			} else {
				l = mid;
			}
		}
		return l;
	}

	int countPow(int m, int n) {
		int ans = 0;
		while (m % n == 0 && m > 0) {
			ans++;
			m /= n;
		}
		return ans;
	}

	long binPow(long a, long b) {
		if (b == 0) {
			return 1;
		}
		if (b % 2 == 1) {
			return a * binPow(a, b - 1);
		} else {
			long c = binPow(a, b / 2);
			return c * c;
		}

	}

	int gcd(int a, int b) {
		return b == 0 ? a : gcd(b, a % b);
	}

	long pow(long x, long k) {
		long ans = 1;
		for (int i = 0; i < k; ++i) {
			ans *= x;
		}
		return ans;
	}

	// ////////////////////////////////////////////////////////////////////

	String delimiter = " ";

	String readLine() throws IOException {
		return in.readLine();
	}

	String rS() throws IOException {
		while (!tok.hasMoreTokens()) {
			String nextLine = readLine();
			if (null == nextLine)
				return null;

			tok = new StringTokenizer(nextLine);
		}

		return tok.nextToken(delimiter);
	}

	int rI() throws IOException {
		return Integer.parseInt(rS());
	}

	long rL() throws IOException {
		return Long.parseLong(rS());
	}

	double rD() throws IOException {
		return Double.parseDouble(rS());
	}

	int[] rA(int b) {
		int a[] = new int[b];
		for (int i = 0; i < b; i++) {
			try {
				a[i] = rI();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return a;
	}

	int[] readSortedIntArray(int size) throws IOException {
		Integer[] array = new Integer[size];

		for (int index = 0; index < size; ++index) {
			array[index] = rI();
		}
		Arrays.sort(array);

		int[] sortedArray = new int[size];
		for (int index = 0; index < size; ++index) {
			sortedArray[index] = array[index];
		}

		return sortedArray;
	}

	int[] sortedIntArray(int size, int[] array) throws IOException {
		for (int index = 0; index < size; ++index) {
			array[index] = rI();
		}
		Arrays.sort(array);

		int[] sortedArray = new int[size];
		for (int index = 0; index < size; ++index) {
			sortedArray[index] = array[index];
		}

		return sortedArray;
	}
}