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:

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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.IOException;
import java.io.InputStream;
import java.util.InputMismatchException;

public class C {
	public static int[] getCols(int t, int[][] mat, int H, int W){
		int[] cols = new int[W];
		for(int i = 0; i<W; i++){
			cols[i] = mat[0][i] - t;
		}
		return cols;
	}
	
	public static int[] getRows(int t, int[][] mat, int H, int W){
		int[] rows = new int[H];
		for(int i = 0; i<H; i++){
			rows[i] = mat[i][0] - t;
		}
		return rows;
	}
	
	public static boolean constuct(int[] rows, int[] cols, int H, int W, int[][] mat){
		int[][] matrix = new int[H][W];
		for(int i = 0; i<H; i++){
			for(int j = 0; j<W; j++){
				matrix[i][j] = rows[i];
			}
		}
		
		for(int j = 0; j<W; j++){
			for(int i = 0; i<H; i++){
				matrix[i][j] += cols[j];
			}
		}
		
		//compare
		for(int i = 0; i<H; i++){
			for(int j = 0; j<W; j++){
				if(mat[i][j] != matrix[i][j]) return false;
			}
		}
		return true;
	}
	
	public static void main(String[] args) {
		FastScannerC sc = new FastScannerC(System.in);
		
		int H = sc.nextInt();
		int W = sc.nextInt();
		int[][] mat = new int[H][W];
		for(int i = 0; i<H; i++){
			for(int j = 0; j<W; j++){
				mat[i][j] = sc.nextInt();
			}
		}
		int minRes = Integer.MAX_VALUE;
		int[] bestCols = null;
		int[] bestRows = null;
		
		for(int t = 0; t <= 500; t++){
			int[] cols = getCols(t, mat, H, W);
			int[] rows = getRows(cols[0], mat, H, W);
			
			//non-negativity check
			boolean valid = true;
			for(int i : cols){
				if(i < 0){
					valid = false;
					break;
				}
			}
			for(int i : rows){
				if(i < 0){
					valid = false;
					break;
				}
			}
			
			if(!valid) continue;
			
			//matrix check;
			boolean good = constuct(rows, cols, H, W, mat);
			if(good){
				int res = 0;
				for(int i : rows) res += i;
				for(int i : cols) res += i;
				if(res < minRes){
					minRes = res;
					bestCols = cols;
					bestRows = rows;
				}
			}
		}
		
		if(minRes == Integer.MAX_VALUE){
			System.out.println(-1);
		}
		else{
			StringBuilder sb = new StringBuilder();
			sb.append(minRes);
			sb.append('\n');
			for(int i = 0; i<H; i++){
				for(int ii = 0; ii<bestRows[i]; ii++){
					sb.append("row ");
					sb.append(i + 1);
					sb.append('\n');
				}
			}
			
			for(int i = 0; i<W; i++){
				for(int ii = 0; ii<bestCols[i]; ii++){
					sb.append("col ");
					sb.append(i + 1);
					sb.append('\n');
				}
			}
			System.out.print(sb);
		}
	}
}

class FastScannerC{
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;

    public FastScannerC(InputStream stream)
    {
        this.stream = stream;
    }

    public int read()
    {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars)
        {
            curChar = 0;
            try
            {
                numChars = stream.read(buf);
            } catch (IOException e)
            {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public int nextInt()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do
        {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public String next()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do
        {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }
    
    public String nextLine()
    {
        int c = read();
        StringBuilder res = new StringBuilder();
        do
        {
            res.appendCodePoint(c);
            c = read();
        } while (!isLineEndChar(c));
        return res.toString();
    }    
    
    public double nextDouble() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        double res = 0;
        while (!isSpaceChar(c) && c != '.') {
            if (c == 'e' || c == 'E')
                return res * Math.pow(10, nextInt());
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        }
        if (c == '.') {
            c = read();
            double m = 1;
            while (!isSpaceChar(c)) {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                m /= 10;
                res += (c - '0') * m;
                c = read();
            }
        }
        return res * sgn;
    }
    
    public long nextLong() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }
    
    public boolean isSpaceChar(int c)
    {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
    
    public boolean isLineEndChar(int c)
    {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == '\n' || c == '\r' || c == -1;
    }

    public interface SpaceCharFilter
    {
        public boolean isSpaceChar(int ch);
    }
}