#include <stdio.h>
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <string>
#include <string.h>
#include <vector>
#include <queue>
#include <stack>
#include <math.h>
#include <cmath>
#include <map>
#include <set>
#include <cstdlib>
#include <utility>
#include <iomanip>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef string st;
typedef pair<int, int> pii;
typedef vector <pair<int, int>> vpii;

struct ver {
	int xv, yv;
	bool h;
};
const int INF = 1e5;
const int SIZE = 501;
char g[SIZE][SIZE];
int used[SIZE][SIZE], dist[SIZE][SIZE], n, m;
pii par[SIZE][SIZE];
deque<ver> q;



bool exist(int x1, int y1) {
	return !(x1 < 0 || x1 >= n || y1 < 0 || y1 >= m);
}

int dx[] = { 1, -1, 0, 0 };
int dy[] = { 0, 0, -1, 1 };
int size_d = 4;

int main() {
	//setlocale(LC_ALL, "Russian");
	//freopen("INPUT.TXT", "r", stdin);
	//freopen("OUTPUT.TXT", "w", stdout);
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> m;
	int xc, yc;
	int xl, yl;
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			cin >> g[i][j];
			if (g[i][j] == 'F') {
				xc = i;
				yc = j;
			}
			if (g[i][j] == 'S') {
				xl = i;
				yl = j;
			}
			if (g[i][j] == 'P') used[i][j] = 1;
			dist[i][j] = INF;
		}
	}
	used[xc][yc] = 1;
	dist[xc][yc] = 0;
	//par[xc][yc] = make_pair(-1, -1);
	q.push_back({ xc, yc, 1 });
	while (!q.empty()) {
		int x = q.front().xv;
		int y = q.front().yv;
		bool h = q.front().h;
		q.pop_front();
		if (h) {
			int tox = x;
			for (int toy = y + 1; toy < n; toy++) {
				if (g[tox][toy] == 'P') break;
				else if (exist(tox, toy) && !used[tox][toy]) {
					used[tox][toy] = 1;
					dist[tox][toy] = dist[x][y] + 1;
					par[tox][toy] = make_pair(x, y);
					q.push_back({ tox, toy, 0 });
				}
			}
			for (int toy = 0; toy < y; toy++) {
				if (g[tox][toy] == 'P') break;
				else if (exist(tox, toy) && !used[tox][toy]) {
					used[tox][toy] = 1;
					dist[tox][toy] = dist[x][y] + 1;
					par[tox][toy] = make_pair(x, y);
					q.push_front({ tox, toy, 0 });
				}
			}
		}
		if(!h || x==xc && y==yc) {
			int toy = y;
			for (int tox = x + 1; tox < m; tox++) {
				if (g[tox][toy] == 'P') break;
				else if (exist(tox, toy) && !used[tox][toy]) {
					used[tox][toy] = 1;
					dist[tox][toy] = dist[x][y] + 1;
					par[tox][toy] = make_pair(x, y);
					q.push_back({ tox, toy, 1 });
				}
			}
			for (int tox = 0; tox < x; tox++) {
				if (g[tox][toy] == 'P') break;
				else if (exist(tox, toy) && !used[tox][toy]) {
					used[tox][toy] = 1;
					dist[tox][toy] = dist[x][y] + 1;
					par[tox][toy] = make_pair(x, y);
					q.push_front({ tox, toy, 1 });
				}
			}
		}
	}
	cout << dist[xl][yl];
}