#include <cstdio>
#include <algorithm>

using namespace std;

const int DUZO = 999999;

char orig[20][20];
char tab[20][20];
int R, C;
int res;

void mark( int x, int y ) {
    if ( x < 0 or x >= R or y < 0 or y >= C )
        return;
    if ( tab[x][y] == 'X' )
        tab[x][y] = '.';
    else
        tab[x][y] = 'X';
}

void strzel( int x, int y ) {
//    printf("strzelam w %d %d\n", x, y);
    mark( x, y );
    mark( x-1, y );
    mark( x+1, y );
    mark( x, y-1 );
    mark( x, y+1 );
}

int fun() {
    scanf("%d %d", &R, &C);
    if ( R == 0 or C == 0 )
        return 1;

    res = DUZO;

    for ( int i = 0; i < R; i++ ) {
        for ( int j = 0; j < C; j++ ) {
            scanf(" %c", &orig[i][j]);
        }
    }


    for ( int l = 0; l < (1<<C); l++ ) { // UWAGA
        int lres = 0;

        // przepisz orig
        for ( int i = 0; i < R; i++ )
            for ( int j = 0; j < C; j++ )
                tab[i][j] = orig[i][j];

        // strzel w wybrane miejsca
        for ( int i = 0; i < 16; i++ ) {
            if ( l & (1<<i) ) {
                strzel( 0, i );
                lres++;
            }
        }

        // jedziemy
        for ( int i = 0; i < R-1; i++ ) {
            for ( int j = 0; j < C; j++ ) {
                if ( tab[i][j] == 'X' ) {
                    strzel(i+1, j);
                    lres++;
                }
            }
        }

        // sprawdz
        int ok = 1;
        for ( int i = 0; i < C; i++ ) {
            if ( tab[R-1][i] == 'X' ) {
                ok = 0;
                break;
            }
        }

        //printf("dla l = %d lres = %d\n", l, lres);
       if ( ok ) {
           res = min( res, lres );
       }
    }

    if ( res == DUZO )
        printf("Damaged billboard.\n");
    else
        printf("You have to tap %d tiles.\n", res);

    return 0;
}

int main() {
    while ( ! fun() );
    return 0;
}