#include <bits/stdc++.h>
using namespace std;
int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
int h, w;
vector<string> adj;
vector<vector<bool>> visited;
bool is_valid(int r, int c) {
return r >= 0 && r < h && c >= 0 && c < w;
}
bool bfs(char t) {
if (adj[0][0] != t) {
return false;
}
queue<pair<int, int>> q;
visited.assign(h, vector<bool>(w, false));
q.push({0, 0});
visited[0][0] = true;
while (!q.empty()) {
pair<int, int> curr = q.front();
q.pop();
int y = curr.first;
int x = curr.second;
if (y == h - 1 && x == w - 1) {
return true;
}
for (int i = 0; i < 4; i++) {
int ny = y + dx[i];
int nx = x + dy[i];
if (is_valid(ny, nx) && adj[ny][nx] == t && !visited[ny][nx]) {
visited[ny][nx] = true;
q.push({ny, nx});
}
}
}
return false;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> h >> w;
adj.resize(h);
bool r = false, f = false;
for (int i = 0; i < h; i++) {
cin >> adj[i];
if (!r || !f) {
for (char c : adj[i]) {
if (c == 'R') r = true;
if (c == 'F') f = true;
if (r && f) break;
}
}
}
if ((r && !f) || (!r && f))
cout << 1;
else if (bfs('R') || bfs('F'))
cout << 2;
else
cout << 3;
}
