#include <bits/stdc++.h>
using namespace std;
const int N = 4005;
int n, m;
char a[N][N];
int c1 = 0, c2 = 0;
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
int vis[N][N];
bool check(int i, int j, char c){
return (i >= 0 && i < n && j >= 0 && j < m && a[i][j] == c && !vis[i][j]);
}
void cover(int i0, int j0){
queue<pair<int, int>> q;
q.push({i0, j0});
vis[i0][j0] = true;
while(!q.empty()){
int i = q.front().first, j = q.front().second; q.pop();
vis[i][j] = true;
if(a[i][j] == 'F') c1--;
if(a[i][j] == 'R') c2--;
for(int op = 0; op < 4; op++){
int i1 = i + dy[op];
int j1 = j + dx[op];
if(check(i1, j1, a[i][j])){
q.push({i1, j1});
}
}
a[i][j] = '.';
}
}
void solve(){
cin >> n >> m;
for(int i = 0; i < n; i++) for(int j = 0; j < m; j++) cin >> a[i][j];
for(int i = 0; i < n; i++) for(int j = 0; j < m; j++){
if(a[i][j] == 'F') c1++;
if(a[i][j] == 'R') c2++;
}
int sol = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
if(c1 == 0 && c2 == 0){ cout << sol << endl; return; }
if(c1 == 0 || c2 == 0){ cout << ++sol << endl; return; }
if(a[i][j] != '.'){
cover(i, j);
sol++;
}
}
}
cout << sol << endl;
}
int32_t main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int t = 1;
// cin >> t;
while(t--) solve();
return 0;
}
