#include <bits/stdc++.h>
// #ifndef ONLINE_JUDGE
// #include <debug.h>
// #else
// #define debug(...)
// #endif
#define GOOD_LUCK ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define int int16_t
#define endl "\n"
#define ff first
#define ss second
#define pb push_back
#define all(v) v.begin(), v.end()
using namespace std;
int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1};
constexpr int MAX = 4e+3 + 1;
int n, m;
char v[MAX+2][MAX+2], col[MAX+2][MAX+2];
vector <pair<int16_t, int16_t>> a, b;
pair<int, int> q[MAX*MAX];
int k = -1;
void dfs(int ux, int uy, char c) {
col[ux][uy] = 1;
a.pb({ux, uy});
for (int z = 0; z < 4; z++) {
int ix = ux + dx[z], iy = uy + dy[z];
if (ix < 0 || iy < 0 || ix >= n || iy >= m) continue;
if (v[ix][iy] != c) continue;
if (col[ix][iy]) continue;
dfs(ix, iy, c);
}
}
void bfs(char c) {
b.clear();
for (auto &i : a) {
k++;
q[k] = i;
}
while (k >= 0) {
auto [ux, uy] = q[k];
q[k] = {-1, -1};
k--;
for (int z = 0; z < 4; z++) {
int ix = ux + dx[z], iy = uy + dy[z];
if (ix < 0 || iy < 0 || ix >= n || iy >= m) continue;
if (col[ix][iy]) continue;
if (v[ix][iy] != c) continue;
b.pb({ix, iy});
k++;
q[k] = {ix, iy};
col[ix][iy] = 1;
}
}
a.swap(b);
}
void _() {
cin >> n >> m;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) cin >> v[i][j];
}
dfs(0, 0, v[0][0]);
array <char, 2> t = {'F', 'R'};
int id = 0;
if (v[0][0] == t[0]) id = 1;
int32_t res = 0;
while (!a.empty()) {
bfs(t[id]);
res++;
id = 1 - id;
}
cout << res;
}
signed main() {
GOOD_LUCK
int tests=1;
// cin >> tests;
for (int i=1; i <= tests; i++) {
_();
cout << endl;
}
return 0;
}
