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

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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:

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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.io.PrintWriter;
import java.util.InputMismatchException;
import java.util.LinkedList;
import java.util.concurrent.CountDownLatch;

public class C {

    private static int n, m;
    private static int pos, len;
    private static int max, min;
    private static int cur, sum;
    private static int ans, res;
    private static int ai, bi, ci, di;
    private static int[] aix, bix, cix;
    private static int[][] aixx, bixx;
    private static long al, bl, cl, dl;
    private static long[] alx, blx;
    private static long[][] alxx, blxx;
    private static double ad, bd, cd, dd;
    private static double[] adx, bdx;
    private static double[][] adxx, bdxx;
    private static boolean ab, bb, cb, db;
    private static boolean[] abx, bbx;
    private static boolean[][] abxx, bbxx;
    private static char ac, bc, cc, dc;
    private static char[] acx, bcx;
    private static char[][] acxx, bcxx;
    private static String as, bs, cs, ds;
    private static String[] asx, bsx;
    private static InputReader in = new InputReader(System.in);
    private static PrintWriter out = new PrintWriter(System.out);

    public static void main(String[] args) {
        int n = in.nextInt();
        int m = in.nextInt();

        aixx = new int[n][m];
        int[] row = new int[n];
        int[] rowt = new int[n];
        int[] col = new int[m];
        int[] colt = new int[m];

        long count = 0;

        // all min
        min = Integer.MAX_VALUE;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                aixx[i][j] = in.nextInt();
                min = Integer.min(min, aixx[i][j]);
            }
        }

        if(n <= m){
            for (int i = 0; i < n; i++) {
                rowt[i] = min;
            }
            count += min * n;
        } else {
            for (int j = 0; j < m; j++) {
                colt[j] = min;
            }
            count += min * m;
        }

        // row min
        for (int i = 0; i < n; i++) {
            int rowi = Integer.MAX_VALUE;
            for (int j = 0; j < m; j++) {
                aixx[i][j] -= min;
                rowi = Integer.min(rowi, aixx[i][j]);
            }
            row[i] = rowi;
            count += rowi;
        }

        for (int j = 0; j < m; j++) {
            int colj = Integer.MAX_VALUE;
            for (int i = 0; i < n; i++) {
                aixx[i][j] -= row[i];
                colj = Integer.min(colj, aixx[i][j]);
            }
            col[j] = colj;
            count += colj;
        }

        boolean isOk = true;

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                aixx[i][j] -= col[j];
                if(aixx[i][j]!=0){
                    isOk = false;
                }
            }
        }

        if(isOk){
            out.println(count);
            for (int i = 0; i < n; i++) {
                while (row[i] -- != 0){
                    out.printf("row %d\n", i+1);
                }
                while (rowt[i] -- != 0){
                    out.printf("row %d\n", i+1);
                }
            }
            for (int j = 0; j < m; j++) {
                while (col[j] -- != 0){
                    out.printf("col %d\n", j+1);
                }
                while (colt[j] -- != 0){
                    out.printf("col %d\n", j+1);
                }
            }
        } else {
            out.println(-1);
        }

        out.close();
    }

    private static class InputReader {

        private InputStream stream;

        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

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

        public String next() {
            return readString();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private String readString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        private 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++];
        }
    }
}