#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld double
const int INF = 1e18;
const int mod = 12345;
const int sz = 4e3 + 5;
int n , m;
char a[sz][sz];
bool vis[sz][sz];
int dx[4] = {1 , -1 , 0 , 0};
int dy[4] = {0 , 0 , 1 , -1};
bool can_go(int x , int y)
{
if(x >= 1 && n >= x && y >= 1 && m >= y && !vis[x][y] && a[x][y] != '.') return true;
else return false;
}
void dfs(int x , int y)
{
for(int i = 0;i < 4;i++)
{
if(can_go(x + dx[i] , y + dy[i]))
{
vis[x + dx[i]][y + dy[i]] = 1;
dfs(x + dx[i] , y + dy[i]);
}
}
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin >> n >> m;
int cnt = 0;
for(int i = 1;i <= n;i++)
{
for(int j = 1;j <= m;j++)
{
cin >> a[i][j];
if(a[i][j] == 'F') cnt++;
}
}
int ans = 0;
while(1)
{
int ansc = ans;
for(int i = 1;i <= n;i++)
{
for(int j = 1;j <= m;j++)
{
if(!vis[i][j] && (a[i][j] == 'R'))
{
vis[i][j] = 1;
dfs(i , j);
ans++;
}
}
}
for(int i = 1;i <= n;i++)
{
for(int j = 1;j <= m;j++)
{
if(!vis[i][j] && (a[i][j] == 'F'))
{
vis[i][j] = 1;
dfs(i , j);
ans++;
}
}
}
if(ans == ansc) break;
}
if(cnt) ans++;
cout << ans << endl;
}
