#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

std::ifstream f("labirint.in");
std::ofstream g("labirint.out");

const int dx[] = { -1 , 1 , 0 , 0 };
const int dy[] = { 0 , 0 , 1 , -1 };

const int NMAX = 1005;
int n,m,cost[NMAX][NMAX],cost2[NMAX][NMAX];
char matrix[NMAX][NMAX];
bool vis[NMAX][NMAX];
std::queue<std::pair<int,int>>Q;
std::vector<std::pair<int,int>>chei;
std::vector<std::pair<int,int>>iesiri;

bool isValid(int i,int j){
    return  i >= 1 && i <= n && j >= 1 && j <= m;
}

int main(){

    f >> n >> m;

    for(int i = 1;i <= n;++i){
        for(int j = 1;j <= m;++j){
            f >> matrix[i][j];
            if(matrix[i][j] == 'A'){
                Q.push({i,j});
                vis[i][j] = true;
                cost[i][j] = 1;
            }else if(matrix[i][j] == 'B'){
                chei.push_back({i,j});
                cost2[i][j] = 1;
            }else if(matrix[i][j] == 'C'){
                iesiri.push_back({i,j});
            }
        }
    }

    // Lee 'A' -> 'B'
    while(!Q.empty()){

        int i = Q.front().first;
        int j = Q.front().second;
        Q.pop();

        for(int dir = 0;dir < 4;++dir){

            int next_i = i + dx[dir];
            int next_j = j + dy[dir];

            if(isValid(next_i,next_j) && !vis[next_i][next_j]){
                if(matrix[next_i][next_j] != 'Z'){
                    vis[next_i][next_j] = true;
                    cost[next_i][next_j] = cost[i][j] + 1;
                    Q.push( {next_i,next_j} );
                }
            }
        }
    }

    while(!Q.empty())
        Q.pop();

    for(int i = 1;i <= n;++i)
        for(int j = 1;j <= m;++j)
            vis[i][j] = false;

    for(auto cheie : chei){
        Q.push(cheie);
        vis[cheie.first][cheie.second] = true;
    }

    // B -> C
    while(!Q.empty()){

        int i = Q.front().first;
        int j = Q.front().second;
        Q.pop();

        for(int dir = 0;dir < 4;++dir){

            int next_i = i + dx[dir];
            int next_j = j + dy[dir];

            if(isValid(next_i,next_j) && !vis[next_i][next_j]){

                if(matrix[next_i][next_j] != 'Z'){
                    if(matrix[next_i][next_j] != 'C'){
                        vis[next_i][next_j] = true;
                        cost2[next_i][next_j] = cost2[i][j] + 1;
                        Q.push( {next_i,next_j} );
                    }else{
                        vis[next_i][next_j] = true;
                        cost2[next_i][next_j] = cost2[i][j];
                        Q.push( {next_i,next_j} );
                    }
                }
            }
        }
    }

    //cost -> chei
    //cost2 ->iesiri

    /*
    for(int i = 1;i <= n;++i,g << '\n')
        for(int j = 1;j <= m;++j)
            g << cost2[i][j] << ' ';
     */

    int sol = (1 << 30);

    for(int i = 0;i < iesiri.size();++i)
        for(int j = 0;j < chei.size();++j)
            if(cost[ chei[j].first ][ chei[j].second ] +
               cost2[ iesiri[i].first ][iesiri[i].second] < sol)
                sol = cost[ chei[j].first ][ chei[j].second ] +
                cost2[ iesiri[i].first ][iesiri[i].second] ;

    g << sol;

    return 0;
}