#include <bits/stdc++.h>
#define ll long long
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pi;
const int INF = 1e9;
const int MX = 5e5 + 23;
const int MOD = 1e9+7;
const int MAX_N = 1e6;
const int MAX_N2 = 1e5;
const int TWO_MOD_INV = 500000004;
const int M = 998244353;
void solve() {
int h,w;
cin >> h >> w;
char grid[h][w];
for(int i=0; i<h; ++i) {
for(int j=0; j<w; ++j) cin >> grid[i][j];
}
int f[h][w], r[h][w], F=0, R=0;
memset(f, 0, sizeof f);
memset(r, 0, sizeof r);
for(int i=0; i<h; ++i) for(int j=0; j<w; ++j) {
if(grid[i][j]!='F' or f[i][j]) continue;
queue<pair<int,int>>q;
q.push({i, j});
++F;
while(!q.empty()) {
int x=q.front().first, y=q.front().second;
q.pop();
f[x][y]=F;
if(x && grid[x-1][y]!='.' && !f[x-1][y]) q.push({x-1, y});
if(y && grid[x][y-1]!='.' && !f[x][y-1]) q.push({x, y-1});
if(x+1<h && grid[x+1][y]!='.' && !f[x+1][y]) q.push({x+1, y});
if(y+1<w && grid[x][y+1]!='.' && !f[x][y+1]) q.push({x, y+1});
}
}
for(int i=0; i<h; ++i) for(int j=0; j<w; ++j) {
if(grid[i][j]!='R' or r[i][j]) continue;
queue<pair<int,int>>q;
q.push({i, j});
++R;
while(!q.empty()) {
int x=q.front().first, y=q.front().second;
q.pop();
r[x][y]=R;
if(x && grid[x-1][y]!='.' && !r[x-1][y]) q.push({x-1, y});
if(y && grid[x][y-1]!='.' && !r[x][y-1]) q.push({x, y-1});
if(x+1<h && grid[x+1][y]!='.' && !r[x+1][y]) q.push({x+1, y});
if(y+1<w && grid[x][y+1]!='.' && !r[x][y+1]) q.push({x, y+1});
}
}
cout << F+R << endl;
}
signed main()
{
//freopen("odometer.in","r",stdin);
//freopen("odometer.out","w",stdout);
int t=1;
while(t--) solve();
return 0;
}
