// In the name of God
// : )
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
typedef long long ll;
const int N = 4000 + 5;
int di[4] = {1, -1, 0, 0}, dj[4] = {0, 0, 1, -1};
int H, W;
string grid[N];
vector<pair<int, int> > V[2];
bool vis[N][N];
bool valid(int x, int y) {
return x >= 0 && y >= 0 && x < H && y < W && grid[x][y] != '.';
}
void dfs(int x, int y, int k) {
V[k].pb(mp(x, y));
vis[x][y] = true;
for (int i = 0; i < 4; i++) {
int x2 = x + di[i];
int y2 = y + dj[i];
if (valid(x2, y2) && !vis[x2][y2] && (grid[x2][y2] == 'F') == k) {
dfs(x2, y2, k);
}
}
}
void solve() {
cin >> H >> W;
for (int i = 0; i < H; i++)
cin >> grid[i];
if (grid[0][0] == '.') {
cout << 0 << '\n';
return;
}
dfs(0, 0, grid[0][0] == 'F');
bool k = grid[0][0] == 'F';
int ans = 0;
while (!V[0].empty() || !V[1].empty()) {
for (auto [x, y] : V[k]) {
for (int i = 0; i < 4; i++) {
int x2 = x + di[i];
int y2 = y + dj[i];
if (valid(x2, y2) && !vis[x2][y2]) {
dfs(x2, y2, grid[x2][y2] == 'F');
}
}
}
V[k].clear();
k ^= 1;
ans++;
}
cout << ans << '\n';
}
int32_t main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
