#include <iostream>
#include <vector>
using namespace std;
int main() {
int H, W;
cin >> H >> W;
vector<string> meadow(H);
for (int i = 0; i < H; ++i) {
cin >> meadow[i];
}
int count = 0;
vector<vector<bool>> visited(H, vector<bool>(W, false));
for (int i = 0; i < H; ++i) {
for (int j = 0; j < W; ++j) {
if (meadow[i][j] == 'R' && !visited[i][j]) {
count++;
for (int x = i; x < H && meadow[x][j] == 'R'; ++x) {
visited[x][j] = true;
}
}
if (meadow[i][j] == 'F' && !visited[i][j]) {
count++;
for (int x = i; x < H && meadow[x][j] == 'F'; ++x) {
visited[x][j] = true;
}
}
}
}
cout << count << endl;
return 0;
}
