#include <iostream>
#include <queue>
using namespace std;

int redovi, koloni;
char lavirint[1000][1000];

int bfs(int si, int sj, int ei, int ej) {
    int poseteno[redovi][koloni];
    for(int i = 0; i < redovi; i++) {
        for(int j = 0; j < koloni; j++) {
            poseteno[i][j] = 0;
        }
    }
    queue<int> Q;
    Q.push(si);
    Q.push(sj);
    Q.push(0);
    poseteno[si][sj] = 1;


    while(Q.size() > 0) {
        int ci = Q.front();
        Q.pop();
        int cj = Q.front();
        Q.pop();
        int cekori = Q.front();
        Q.pop();

        if(ci == ei and cj == ej) {

            return cekori;
        }
        if(ci + 1 < redovi and lavirint[ci + 1][cj] != '#' and poseteno[ci + 1][cj] == 0) {
            Q.push(ci + 1);
            Q.push(cj);
            Q.push(cekori + 1);
            poseteno[ci + 1][cj] = 1;
        }
        if(ci - 1 >= 0 and lavirint[ci - 1][cj] != '#' and poseteno[ci - 1][cj] == 0) {
            Q.push(ci - 1);
            Q.push(cj);
            Q.push(cekori + 1);
            poseteno[ci - 1][cj] = 1;
        }
        if(cj + 1 < koloni and lavirint[ci][cj + 1] != '#' and poseteno[ci][cj + 1] == 0) {
            Q.push(ci);
            Q.push(cj + 1);
            Q.push(cekori + 1);
            poseteno[ci][cj + 1] = 1;
        }
        if(cj - 1 >= 0 and lavirint[ci][cj - 1] != '#' and poseteno[ci][cj - 1] == 0) {
            Q.push(ci);
            Q.push(cj - 1);
            Q.push(cekori + 1);
            poseteno[ci][cj - 1] = 1;
        }
    }
    return 0;
}
int main()
{
    cin >> redovi >> koloni;
    int si, sj;
    int ai, aj;
    int bi, bj;
    int pi, pj;
    for(int i = 0; i < redovi; i++) {
        for(int j = 0; j < koloni; j++) {
            cin >> lavirint[i][j];

            if(lavirint[i][j] == 'S') {
                si = i;
                sj = j;
            }
            if(lavirint[i][j] == 'A') {
                ai = i;
                aj = j;
            }
            if(lavirint[i][j] == 'B') {
                bi = i;
                bj = j;
            }
            if(lavirint[i][j] == 'P') {
                pi = i;
                pj = j;
            }
        }
    }
    int pat1 = bfs(si, sj, ai, aj) + bfs(ai, aj, pi, pj);
    int pat2 = bfs(si, sj, bi, bj) + bfs(bi, bj, pi, pj);

    if(pat1 < pat2) {
        cout << pat1 << endl;
    }
    else {
        cout << pat2 << endl;
    }
       return 0;
}

/*

8 8
S...#..A
........
...#P...
B.......
##......
########
........
........


 **/