#include<bits/stdc++.h>
using namespace std;
const int MXN = 4000, INF = 1e9 + 5;
const int MOD = 1e9 + 7;
int n, m;
char arr[MXN][MXN];
bool vis[MXN][MXN];
char now;
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
void dfs(int x, int y){
if(x < 0 || x >= n || y < 0 || y >= m || vis[x][y] || arr[x][y] != now) return;
vis[x][y] = 1;
for(int i = 0; i < 4; i++){
dfs(x + dx[i], y + dy[i]);
}
}
void solve(){
cin >> n >> m;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
cin >> arr[i][j];
}
}
now = 'R';
int cnt1 = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
if(!vis[i][j] && arr[i][j] == 'R') cnt1++, dfs(i, j);
}
}
now = 'F';
int cnt2 = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
if(!vis[i][j] && arr[i][j] == 'F') cnt2++, dfs(i, j);
}
}
cout << min(cnt1, cnt2) + 1 << endl;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(0);
cerr.tie(0);
// freopen("filename.in", "r", stdin);
// freopen("filename.out", "w", stdout);
int TC = 1;
// cin >> TC;
while(TC--) solve();
return 0;
}
