#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int h, w;
cin >> h >> w;
vector<string> map(h);
int tt = 0;
for (int i = 0; i < h; i++) {
cin >> map[i];
for (char x: map[i]) {
tt += (x!='.')? 1:0;
}
}
char cur = map[0][0];
vector<vector<int>> visited(h, vector<int>(w));
vector<int> xdirs = {-1, 0, 1, 0};
vector<int> ydirs = {0, -1, 0, 1};
int ans = 0;
deque<pair<int, int>> stack;
while (tt > 0) {
ans++;
stack.push_back({0, 0});
while (!stack.empty()) {
auto [x, y] = stack.at(0);
stack.pop_front();
for (int i = 0; i < 4; i++) {
int nx = x + xdirs[i];
int ny = y + ydirs[i];
if (nx < 0 || nx >= h || ny < 0 || ny >= w) continue;
if ((map[nx][ny] == cur || map[nx][ny] == 'c') && visited[nx][ny] != ans) {
if (map[nx][ny] == cur) tt--;
map[nx][ny] = 'c';
visited[nx][ny] = ans;
stack.push_back({nx, ny});
}
}
}
if (cur == 'F') {
cur = 'R';
} else {
cur = 'F';
}
}
cout << ans;
}
