#include <iostream>
#include <cstdio>
#include <queue>
#include <cstdlib>
#include <cstring>

using namespace std;

struct node {
    int i;
    int j;
};

struct node make_node ( int i , int j ) {

    struct node n;
    n.i = i;
    n.j = j;
    return n;
}


int main( int argc , char * argv[] ) {

    int r , c;
    int lo = 1;

    char d[50][50];
    int a[50][50];
    int visited[50][50];

    scanf("%d %d" , &r,&c);

    while ( r != 0 && c != 0 ) {

        int i = 0;
        int max = 0;

        for ( i = 0 ; i < r ; i++ ) {
            scanf("%s" , d[i]);
        }

        memset( a , 0 , sizeof( a ) );
        memset( visited , 0 , sizeof( visited ) );

        queue< node > q;

        for ( int i = 0 ; i < r ; i++ ) {
            for ( int j = 0 ; j < c ; j++ ) {
                if ( d[i][j] == 'A' ) {

                    max = 1;
                    a[i][j] = 1;
                    q.push( make_node(i,j) );
                }
            }
        }

        int m1[] = {-1,0,1,1,1,0,-1,-1};
        int m2[] = {-1,-1,-1,0,1,1,1,0};


        while ( !q.empty() ) {

            struct node n = q.front();
            q.pop();

            for ( int i = 0 ; i < 8 ; i++ ) {
                int x = m1[i] + n.i;
                int y = m2[i] + n.j;

                if ( x >= 0 && x < r && y >= 0 && y < c && (d[x][y] == (d[n.i][n.j] + 1)) ) {

                    if ( !visited[x][y] ) {

                        visited[x][y] = 1;

                        a[x][y] = a[n.i][n.j] + 1;

                        if ( a[x][y] > max )
                            max = a[x][y];

                        q.push ( make_node(x,y) );
                    }

                }

            }

        }
        /*for ( int i = 0 ; i < r ; i++ ) {
            for ( int j = 0 ; j < c ; j++ ) {
                printf("%d " , a[i][j] );
            }
            printf("\n");
        }*/
        printf("Case %d: %d\n",lo++,max) ;
        scanf("%d%d" , &r , &c );
    }

    return 0;
}