#include <vector>
#include <algorithm>
#include <fstream>
#include<string>
#include <iostream>
using namespace std;

vector<vector<char> > x(1001, vector<char>(1001));
vector<vector<int> > y(0, vector<int>(2)), rang(1001, vector<int >(1001, -1));
vector<int> q(2);
ifstream in("rook.in"); ofstream out("rook.out");



int main() {
    vector<vector<int> > t(501, vector<int>(501, 0));
    int n, m;
    in >> n >> m;
    string s;
    vector<int> start(2), endd(2);
    getline(in, s);
    for (int i = n - 1; i >= 0; --i) {
        for (int j = 0; j<m; j++) {
            in >> x[i][j];
            if (x[i][j] == 'S') { start[0] = i; start[1] = j; }
            if (x[i][j] == 'F') { endd[0] = i; endd[1] = j; }

        }
    }
    int k = 0;
    vector<int> q(2);
    y.push_back(start);
    rang[start[0]][start[1]] = 0;
    while (k<y.size() ) {
        if (t[y[k][0]][y[k][1]] == 0) {
            t[y[k][0]][y[k][1]] = 1;
            int i;
            int j;
            //cout<<k<<' '<<y[k][0]<<' '<<y[k][1]<<' '<<rang[y[k][0]][y[k][1]]<<endl;
            for (i = y[k][0] + 1; i<n && (x[i][y[k][1]] != 'P'); i++) {

                if (rang[i][y[k][1]] == -1) {
                    q[0] = i;
                    q[1] = y[k][1];
                    y.push_back(q);
                    rang[i][y[k][1]] = rang[y[k][0]][y[k][1]] + 1;
                }
            }
            for (i = y[k][0] - 1; i >= 0 && (x[i][y[k][1]] != 'P'); --i) {
                if (rang[i][y[k][1]] == -1) {
                    q[0] = i;
                    q[1] = y[k][1];
                    y.push_back(q);
                    rang[i][y[k][1]] = rang[y[k][0]][y[k][1]] + 1;
                }
            }


            for (j = y[k][1] - 1; j >= 0 && (x[y[k][0]][j] != 'P'); --j) {
                if (rang[y[k][0]][j] == -1) {
                    q[1] = j;
                    q[0] = y[k][0];
                    y.push_back(q);
                    rang[y[k][0]][j] = rang[y[k][0]][y[k][1]] + 1;
                }
            }

            for (j = y[k][1] + 1; j<m && (x[y[k][0]][j] != 'P'); j++) {
                if (rang[y[k][0]][j] == -1) {
                    q[1] = j;
                    q[0] = y[k][0];
                    y.push_back(q);
                    rang[y[k][0]][j] = rang[y[k][0]][y[k][1]] + 1;
                }
            }
        }
        k++;

    }
    out << rang[endd[0]][endd[1]];
    cin >> k;
    return(0);
}