public class Main implements java.lang.Runnable {
    static MyPrintWriter pw = MyPrintWriter.getInstance();

    static FastScanner sc = FastScanner.getInstance();

    public static void main(java.lang.String[] args) throws java.io.IOException {
        new Main().run();
        Main.pw.flush();
        // JavaToCpp.export();
    }

    int N;

    int[][] d;

    int K;

    @java.lang.Override
    public void run() {
        N = Main.sc.nextInt();
        K = Main.sc.nextInt();
        char[][] cs = Main.sc.nextChars(N, N);
        d = new int[N][N];
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                d[i][j] = cs[i][j] - '0';
            }
        }
        java.util.ArrayList<IntPoint> list = new java.util.ArrayList<>();
        for (int i = 0; i < N; i++) {
            if (d[i][N / 2] != 0) {
                list.add(new IntPoint(i, N / 2));
                d[i][N / 2] = 0;
            }
        }
        for (int i = 0; i < N; i++) {
            if (d[N / 2][i] != 0) {
                list.add(new IntPoint(N / 2, i));
                d[N / 2][i] = 0;
            }
        }
        Main.pw.println(list.size());
        for (int i = 0; i < list.size(); i++) {
            var p = list.get(i);
            Main.pw.println((p.x() + " ") + p.y());
        }
        Main.pw.flush();
    }

    void tr(java.lang.Object... objects) {
        java.lang.System.out.println(java.util.Arrays.deepToString(objects));
    }
}

class FastScanner {
    private static FastScanner instance = null;

    private final java.io.InputStream in = java.lang.System.in;

    private final byte[] buffer = new byte[1 << 16];

    private int ptr = 0;

    private int buflen = 0;

    private FastScanner() {
    }

    public static FastScanner getInstance() {
        if (FastScanner.instance == null) {
            FastScanner.instance = new FastScanner();
        }
        return FastScanner.instance;
    }

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }
        ptr = 0;
        try {
            buflen = in.read(buffer);
        } catch (java.io.IOException e) {
            e.printStackTrace();
        }
        return buflen > 0;
    }

    private int readByte() {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    }

    private boolean isPrintableChar(int c) {
        return (33 <= c) && (c <= 126);
    }

    public boolean hasNext() {
        while (hasNextByte() && (!isPrintableChar(buffer[ptr]))) {
            ptr++;
        } 
        return hasNextByte();
    }

    public java.lang.String next() {
        if (!hasNext()) {
            throw new java.util.NoSuchElementException();
        }
        java.lang.StringBuilder sb = new java.lang.StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        } 
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) {
            throw new java.util.NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        while ((b >= '0') && (b <= '9')) {
            // n = n * 10 + (b - '0');
            n = ((n << 1) + (n << 3)) + (b - '0');
            b = readByte();
        } 
        return minus ? -n : n;
    }

    public int nextInt() {
        return ((int) (nextLong()));
    }

    public char[][] nextChars(int H, int W) {
        if (W == 0) {
            return new char[H][0];
        }
        char[][] a = new char[H][];
        for (int i = 0; i < H; i++) {
            a[i] = next().toCharArray();
        }
        return a;
    }
}

class IntPoint {
    int x;

    int y;

    public IntPoint(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int x() {
        return x;
    }

    public int y() {
        return y;
    }

    /**
     * この点と別のオブジェクトの同値性を判定します。
     *
     * <p>計算量: O(1)</p>
     *
     * @param obj
     * 		比較対象のオブジェクト
     * @return 同値であれば true, そうでなければ false
     */
    // 未テスト
    @java.lang.Override
    public boolean equals(java.lang.Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof IntPoint)) {
            return false;
        }
        IntPoint other = ((IntPoint) (obj));
        return (x == other.x) && (y == other.y);
    }

    /**
     * この点のハッシュコードを計算します。
     *
     * <p>計算量: O(1)</p>
     *
     * @return ハッシュコード
     */
    // 未テスト
    @java.lang.Override
    public int hashCode() {
        return java.util.Objects.hash(x, y);
    }

    @java.lang.Override
    public java.lang.String toString() {
        return ((("(" + x) + ",") + y) + ")";
    }
}

class MyPrintWriter extends java.io.PrintWriter {
    private static MyPrintWriter instance = null;

    private MyPrintWriter() {
        super(java.lang.System.out);
    }

    public static MyPrintWriter getInstance() {
        if (MyPrintWriter.instance == null) {
            MyPrintWriter.instance = new MyPrintWriter();
        }
        return MyPrintWriter.instance;
    }

    public MyPrintWriter(java.io.PrintStream out) {
        super(out);
    }
}


// --- Original Code ---
// import java.io.IOException;
// import java.util.ArrayList;
// import java.util.Arrays;
// import java.util.Random;
// 
// import library.tools.FastScanner;
// import library.tools.JavaToCpp;
// import library.tools.MergeFiles;
// import library.tools.MyPrintWriter;
// import library.util.Fp;
// import library.util.geometry.IntPoint;
// import library.util.polynomial.PolynomialFpDynamic;
// 
// public class Main implements Runnable {
// 
// 	static MyPrintWriter pw=MyPrintWriter.getInstance();
// 	static FastScanner sc=FastScanner.getInstance();
// 	
// 	public static void main(String[] args) throws IOException {
// 		new Main().run();
// 		pw.flush();
// 		MergeFiles.export();
// //		JavaToCpp.export();
// 	}
// 	
// 	Random r=new Random();
// 	
// 	int N;
// 	int[][]d;
// 	int K;
// 	
//     @java.lang.Override
//     public void run() {
//     	N=sc.nextInt();
//     	K=sc.nextInt();
//     	char[][]cs=sc.nextChars(N, N);
//     	d=new int[N][N];
//     	for (int i = 0; i < N; i++) {
// 			for (int j = 0; j < N; j++) {
// 				d[i][j]=cs[i][j]-'0';
// 			}
// 		}
//     	ArrayList<IntPoint> list=new ArrayList<>();
//     	tr("!");
//     	for (int i = 0; i < N; i++) {
// 			if(d[i][N/2]!=0) {
// 				list.add(new IntPoint(i, N/2));
// 				d[i][N/2]=0;
// 			}
// 		}
//     	for (int i = 0; i < N; i++) {
// 			if(d[N/2][i]!=0) {
// 				list.add(new IntPoint(N/2, i));
// 				d[N/2][i]=0;
// 			}
// 		}
//     	pw.println(list.size());
//     	for (int i = 0; i < list.size(); i++) {
//     		var p=list.get(i);
//     		pw.println(p.x()+" "+p.y());
//     	}
//     	pw.flush();
//     }
//     
// 	
// 	int id(int i, int j) {
// 		return N*i+j;
// 	}
// 	
// 	
// 	void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));}
// 	
// 	
// }
//