#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <cmath>
// Dla macOs zachowaj includy w przeciwnym wypadku zastąp "#include <bits/stdc++.h> "
// szybki kod
#define all(v) (v).begin(), (v).end()
#define rep(i, a, b) for(int i = a;i <= b; i++)
#define per(i, a, b) for(int i = a;i >= b; i--)
#define pb push_back
#define ins insert
#define st first
#define nd second
#define test int tc; cin>>tc; while(tc--)
// struktury danych
#define smldi set<map<long double, int > >
#define spumldidsi set<pair<unordered_map<long double, int>, deque<set<long long> > > >
// funkcje wspomagajace debugowanie programu
#define printv(a) { for(auto u : a) cout<<u<<" "; cout<<"/n"; }
#define debug(x) cerr << #x << " = " << x << endl;
// usingi
using namespace std;
using ll = long long;
using pii = pair<int,int>;
using vi = vector<int>;
using si = set<int>;
using mii = map<int,int>;
using bigi = __int128;
int n,m;
vector<pii> dir = {{0,1},{0,-1},{1,0},{-1,0}};
queue<pii> nowe;
char grid[4005][4005];
char turn;
bool czy_moge(int x,int y){
return x >= 0 && x < n && y >= 0 && y < m;
}
void bfs(queue<pii> q){
while(!nowe.empty()){
nowe.pop();
}
while(!q.empty()){
auto [x,y] = q.front();
q.pop();
if(grid[x][y] == '.') continue;
grid[x][y] = '.';
for(auto [dx,dy] : dir){
if(czy_moge(x + dx,y + dy) && grid[x + dx][y + dy] == turn){
q.push({x + dx, y + dy});
}
if(czy_moge(x + dx,y + dy) && grid[x + dx][y + dy] != turn && grid[x + dx][y + dy] != '.'){
nowe.push({x + dx, y + dy});
}
}
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n>>m;
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
cin>>grid[i][j];
}
}
turn = grid[0][0];
nowe.push({0,0});
int wyn = 0;
while(!nowe.empty()){
wyn++;
bfs(nowe);
turn = (turn == 'F' ? 'R' : 'F');
}
cout<<wyn<<endl;
return 0;
}
