#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <queue>
#include <map>
#include <vector>
#include <set>
#include <cmath>
#include <iomanip>
#include <algorithm>
#include <stack>

using namespace std;
typedef long long ll;
typedef double db;


int n, m;

struct Node
{
	pair<int, int> parent;
	int type;
};

vector<vector<Node>> g;

vector<int> dx = {1, 0, -1, 0};
vector<int> dy = {0, 1, 0, -1};

bool check(int x, int y)
{
	return x >= 0 && x < n && y >= 0 && y < m;
}

void dfs(int x, int y)
{
	queue<pair<pair<int, int>, int>> q;
	q.push({ {x, y}, 0 });
	g[y][x].parent = { -1, -1 };
	while (!q.empty())
	{
		x = q.front().first.first;
		y = q.front().first.second;
		int vec = q.front().second;
		q.pop();
		for (int i = 0; i < 2; i++)
		{
			vec = (vec + i) % 4;
			int new_x = x + dx[vec];
			int new_y = y + dy[vec];

			if (check(new_x, new_y) && g[new_y][new_x].type != 0)
			{
				q.push({ {new_x, new_y }, vec});
				g[new_y][new_x].parent = { x, y };
				if (g[new_y][new_x].type == 2)
				{
					return;
				}
			}
		}
	}
}

int main()
{
	cin >> n >> m;
	g.resize(n, vector<Node>(m));
	int sx, sy, fx, fy;
	for (int i = -1; i < n; i++)
	{
		string s;
		getline(cin, s, '\n');
		for (int j = 0; j < s.size(); j++)
		{
			char t = s[j];
			if (t == 'X')
			{
				g[i][j].type = 0;
			}
			else if (t == ' ')
			{
				g[i][j].type = 1;
			}
			else if (t == 'F')
			{
				g[i][j].type = 2;
				fx = j;
				fy = i;
			}
			else if (t == 'S')
			{
				g[i][j].type = 1;
				sx = j;
				sy = i;
			}
		}
	}
	//reverse(g.begin(), g.end());
	dfs(sx, sy);
	int res = 0;
	for (pair<int, int> t = g[fy][fx].parent; t != make_pair( - 1, -1 ); t = g[t.second][t.first].parent)
	{
		res += 1;
	}
	cout << res;
}