A star is a figure of the following type: an asterisk character '*' in the center of the figure and four rays (to the left, right, top, bottom) of the same positive length. The size of a star is the length of its rays. The size of a star must be a positive number (i.e. rays of length 0 are not allowed).

Let's consider empty cells are denoted by '.', then the following figures are stars:

<image> The leftmost figure is a star of size 1, the middle figure is a star of size 2 and the rightmost figure is a star of size 3.

You are given a rectangular grid of size n × m consisting only of asterisks '*' and periods (dots) '.'. Rows are numbered from 1 to n, columns are numbered from 1 to m. Your task is to draw this grid using any number of stars or find out that it is impossible. Stars can intersect, overlap or even coincide with each other. The number of stars in the output can't exceed n ⋅ m. Each star should be completely inside the grid. You can use stars of same and arbitrary sizes.

In this problem, you do not need to minimize the number of stars. Just find any way to draw the given grid with at most n ⋅ m stars.

Input

The first line of the input contains two integers n and m (3 ≤ n, m ≤ 1000) — the sizes of the given grid.

The next n lines contains m characters each, the i-th line describes the i-th row of the grid. It is guaranteed that grid consists of characters '*' and '.' only.

Output

If it is impossible to draw the given grid using stars only, print "-1".

Otherwise in the first line print one integer k (0 ≤ k ≤ n ⋅ m) — the number of stars needed to draw the given grid. The next k lines should contain three integers each — x_j, y_j and s_j, where x_j is the row index of the central star character, y_j is the column index of the central star character and s_j is the size of the star. Each star should be completely inside the grid.

Examples

Input

6 8
....*...
...**...
..*****.
...**...
....*...
........


Output

3
3 4 1
3 5 2
3 5 1


Input

5 5
.*...
****.
.****
..**.
.....


Output

3
2 2 1
3 3 1
3 4 1


Input

5 5
.*...
***..
.*...
.*...
.....


Output

-1


Input

3 3
*.*
.*.
*.*


Output

-1

Note

In the first example the output 
    
    
    2  
    3 4 1  
    3 5 2  
    

is also correct.

import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;
import java.util.Random;
import java.util.StringTokenizer;

public class Main {

    final long b = 31;
    String fileName = "";


    //////////////////////    SOLUTION   SOLUTION  SOLUTION    //////////////////////////////
    int INF = Integer.MAX_VALUE/10;
    long MODULO = 1000_1000_100l;
    int MAX_VALUE = 1000_1000;
    long sum = 0;
    void solve() throws IOException {
        int n = readInt();
        int m = readInt();

        char[][] field = new char[n][m];

        for (int i=0; i<n; ++i){
            field[i] = readString().toCharArray();
        }

        TreeSet<Integer>[] columns = new TreeSet[m];
        TreeSet<Integer>[] rows = new TreeSet[n];

        for (int i=0; i<n; ++i) rows[i] = new TreeSet<>();
        for (int j=0; j<m; ++j) columns[j] = new TreeSet<>();

        for (int i=0; i<n; ++i){
            rows[i].add(-1);
            rows[i].add(m);
            for (int j=0; j<m; ++j){
                columns[j].add(-1);
                columns[j].add(n);
                if (field[i][j] == '.'){
                    rows[i].add(j);
                    columns[j].add(i);
                }
            }
        }

        long[][] plusRows = new long[n][m];
        long[][] minusRows = new long[n][m];
        long[][] plusColumns = new long[n][m];
        long[][] minusColumns = new long[n][m];
        boolean[][] done = new boolean[n][m];
        ArrayList<Star> ansList = new ArrayList<>();
        for (int i=0; i<n; ++i){
            for (int j=0; j<m; ++j){
                if (field[i][j] == '*'){
                    int left = rows[i].lower(j);
                    int right = rows[i].higher(j);
                    int up = columns[j].lower(i);
                    int down = columns[j].higher(i);
                    int len = INF;
                    len = Math.min(len, Math.abs(j - right));
                    len = Math.min(len, Math.abs(j - left));
                    len = Math.min(len, Math.abs(i - up));
                    len = Math.min(len, Math.abs(i - down));

                    if (len > 1){
                        plusRows[i][j-len+1]++;
                        minusRows[i][j+len-1]++;
                        minusColumns[i+len-1][j]++;
                        plusColumns[i-len+1][j]++;
                        ansList.add(new Star(i + 1, j + 1, len - 1));
                    }
                }
            }
        }
        
        for (int i=0; i<n; ++i){
            int bal = 0;
            for (int j=0; j<m; ++j){
                bal += plusRows[i][j];
                if (bal > 0 || field[i][j] == '.') done[i][j] = true;
                bal -= minusRows[i][j];
            }
        }
        for (int j=0; j<m; ++j){
            long bal = 0;
            for (int i=0; i<n; ++i){
                bal += plusColumns[i][j];
                if (bal > 0 || field[i][j] == '.') done[i][j] = true;
                if (!done[i][j]){
                    out.println(-1);
                    return;
                }
                bal -= minusColumns[i][j];
            }
        }
        out.println(ansList.size());

        for (Star star: ansList){
            out.println(star.x +" "+star.y+" "+star.len);
        }
    }
    class Star{
        int x, y, len;
        Star(int x, int y, int len){
            this.x = x;
            this.len = len;
            this.y = y;
        }
    }

    class Number implements Comparable<Number>{
        int x, cost;
        Number(int x, int cost){
            this.x = x;
            this.cost = cost;
        }

        @Override
        public int compareTo(Number o) {
            return Integer.compare(this.cost, o.cost);
        }
    }
    class Point{
        int x, y;
        Point(int x, int y){
            this.x = x;
            this.y = y;
        }
    }

    class Vertex implements Comparable<Vertex>{
        int num, depth, e, c;
        Vertex(int num, int depth, int e, int c){
            this.num = num;
            this.e = e;
            this.depth = depth;
            this.c = c;
        }

        @Override
        public int compareTo(Vertex o) {
            return Integer.compare(this.e, o.e);
        }
    }
    ///////////////////////////////////////////////////////////////////////////////////////////

    class Edge{
        int from, to, num;
        Edge(int to, int num){
            this.to = to;
            this.num = num;
        }
    }

    class SparseTable{
        int[][] rmq;
        int[] logTable;
        int n;
        SparseTable(int[] a){
            n = a.length;
            logTable = new int[n+1];
            for(int i = 2; i <= n; ++i){
                logTable[i] = logTable[i >> 1] + 1;
            }
            rmq = new int[logTable[n] + 1][n];
            for(int i=0; i<n; ++i){
                rmq[0][i] = a[i];
            }

            for(int k=1; (1 << k) < n; ++k){
                for(int i=0; i + (1 << k) <= n; ++i){
                    int max1 = rmq[k - 1][i];
                    int max2 = rmq[k-1][i + (1 << (k-1))];
                    rmq[k][i] = Math.max(max1, max2);
                }
            }
        }

        int max(int l, int r){
            int k = logTable[r - l];
            int max1 = rmq[k][l];
            int max2 = rmq[k][r - (1 << k) + 1];
            return Math.max(max1, max2);
        }
    }
    long checkBit(long mask, int bit){
        return (mask >> bit) & 1;
    }
    class Dsu{
        int[] parent;
        int countSets;
        Dsu(int n){
            countSets = n;
            parent = new int[n];
            for(int i=0; i<n; ++i){
                parent[i] = i;
            }
        }
        int findSet(int a){
            if(parent[a] == a) return a;
            parent[a] = findSet(parent[a]);
            return parent[a];
        }
        void unionSets(int a, int b){
            a = findSet(a);
            b = findSet(b);
            if(a!=b){
                countSets--;
                parent[a] = b;
            }
        }
    }
    static int checkBit(int mask, int bit) {
        return (mask >> bit) & 1;
    }
    boolean isLower(char c){
        return c >= 'a' && c <= 'z';
    }

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

    class SegmentTree{
        int[] t;
        int n;
        SegmentTree(int n){
            t = new int[4*n];
            build(new int[n+1], 1, 1, n);
        }
        void build (int a[], int v, int tl, int tr) {
            if (tl == tr)
                t[v] = a[tl];
            else {
                int tm = (tl + tr) / 2;
                build (a, v*2, tl, tm);
                build (a, v*2+1, tm+1, tr);
            }
        }

        void update (int v, int tl, int tr, int l, int r, int add) {
            if (l > r)
                return;
            if (l == tl && tr == r)
                t[v] += add;
            else {
                int tm = (tl + tr) / 2;
                update (v*2, tl, tm, l, Math.min(r,tm), add);
                update (v*2+1, tm+1, tr, Math.max(l,tm+1), r, add);
            }
        }

        int get (int v, int tl, int tr, int pos) {
            if (tl == tr)
                return t[v];
            int tm = (tl + tr) / 2;
            if (pos <= tm)
                return t[v] + get (v*2, tl, tm, pos);
            else
                return t[v] + get (v*2+1, tm+1, tr, pos);
        }
    }
    class Fenwik {
        long[] t;
        int length;

        Fenwik(int[] a) {
            length = a.length + 100;
            t = new long[length];

            for (int i = 0; i < a.length; ++i) {
                inc(i, a[i]);
            }
        }

        void inc(int ind, int delta) {
            for (; ind < length; ind = ind | (ind + 1)) {
                t[ind] = Math.max(delta, t[ind]);
            }
        }

        long getMax(int r) {
            long sum = 0;
            for (; r >= 0; r = (r & (r + 1)) - 1) {
                sum = Math.max(sum, t[r]);
            }
            return sum;
        }
    }
    int gcd(int a, int b){
        return b == 0 ? a : gcd(b, a%b);
    }
    long gcd(long a, long b){
        return b == 0 ? a : gcd(b, a%b);
    }
    double binPow(double a, int pow){
        if (pow == 0) return 1;
        if (pow % 2 == 1) {
            return a * binPow(a, pow - 1);
        } else {
            double c = binPow(a, pow / 2);
            return c * c;
        }
    }
    long binPow(long a, long b, long m) {
        if (b == 0) {
            return 1;
        }
        if (b % 2 == 1) {
            return ((a % m) * (binPow(a, b - 1, m) % m)) % m;
        } else {
            long c = binPow(a, b / 2, m);
            return (c * c) % m;
        }

    }
    int minInt(int... values) {
        int min = Integer.MAX_VALUE;
        for (int value : values) min = Math.min(min, value);
        return min;
    }

    int maxInt(int... values) {
        int max = Integer.MIN_VALUE;
        for (int value : values) max = Math.max(max, value);
        return max;
    }
    public static void main(String[] args) throws NumberFormatException, IOException {
        // TODO Auto-generated method stub
        new Main().run();
    }

    void run() throws NumberFormatException, IOException {
        solve();
        out.close();
    };

    BufferedReader in;
    PrintWriter out;

    StringTokenizer tok;
    String delim = " ";
    Random rnd = new Random();

    Main() throws FileNotFoundException {
        try {
            in = new BufferedReader(new FileReader("input.txt"));
            out = new PrintWriter("output.txt");
        } catch (Exception e) {
            if (fileName.isEmpty()) {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            } else {
                in = new BufferedReader(new FileReader(fileName + ".in"));
                out = new PrintWriter(fileName + ".out");
            }

        }
        tok = new StringTokenizer("");
    }

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

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

            tok = new StringTokenizer(nextLine);
        }
        return tok.nextToken();
    }

    int readInt() throws NumberFormatException, IOException {
        return Integer.parseInt(readString());
    }
    byte readByte() throws NumberFormatException, IOException {
        return Byte.parseByte(readString());
    }
    int[] readIntArray (int n) throws NumberFormatException, IOException {
        int[] a = new int[n];
        for(int i=0; i<n; ++i){
            a[i] = readInt();
        }
        return a;
    }

    Integer[] readIntegerArray (int n) throws NumberFormatException, IOException {
        Integer[] a = new Integer[n];
        for(int i=0; i<n; ++i){
            a[i] = readInt();
        }
        return a;
    }

    long readLong() throws NumberFormatException, IOException {
        return Long.parseLong(readString());
    }

    double readDouble() throws NumberFormatException, IOException {
        return Double.parseDouble(readString());
    }
}
