#include <bits/stdc++.h>
using namespace std;
const int mxN = 4000;
int di[] = {1, -1, 0, 0};
int dj[] = {0, 0, 1, -1};
char G[mxN][mxN];
bool vis[mxN][mxN];
int N, M;
bool valid(int i, int j) {
return 0 <= i && i < N && 0 <= j && j < M;
}
void dfs(int i, int j, bool which) {
if (vis[i][j]) return;
vis[i][j] = 1;
for (int d = 0; d < 4; ++d)
if (valid(i + di[d], j + dj[d]) && (G[i + di[d]][j + dj[d]] == 'R') == which)
dfs(i + di[d], j + dj[d], which);
}
void solve() {
cin >> N >> M;
for (int i = 0; i < N; ++i)
for (int j = 0; j < M; ++j)
cin >> G[i][j];
bool dis[2] = {};
dfs(0, 0, G[0][0] == 'R');
for (int i = 0; i < N; ++i) {
for (int j = 0; j < M; ++j) {
if (G[i][j] == '.' || vis[i][j]) continue;
bool which = (G[i][j] == 'R');
dis[which] = 1;
dfs(i, j, which);
}
}
cout << 1 + dis[0] + dis[1] << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
return 0;
}
