#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
using namespace std;
// void solve(vector<vector<char>> &grid,char cur,int x, int y)
// {
// if(x>=grid.size()||x<0||y>=grid[0].size()||y<0)
// return;
// if(grid[x][y]!=cur)
// return;
// grid[x][y] = (grid[x][y]=='F')?'R':'F';
// solve(grid,cur,x,y+1);
// solve(grid,cur,x,y-1);
// solve(grid,cur,x+1,y);
// solve(grid,cur,x-1,y);
// }
int single(vector<vector<char>> &grid)
{
int c1 = 0,c2=0;
for(int i=0;i<grid.size();i++)
{
for(int j=0;j<grid[0].size();j++)
{
if(grid[i][j]=='F')
c1++;
else if(grid[i][j]=='R')
c2++;
}
}
if(c1==0&&c2==0)
return -1;
else if(c1==0||c2==0)
return 1;
else
return 0;
}
// int main()
// {
// int h,w;cin>>h>>w;
// vector<vector<char>> grid(h,vector<char>(w));
// for(int i=0;i<h;i++)
// {
// for(int j=0;j<w;j++)
// {
// cin>>grid[i][j];
// }
// }
// if(single(grid)==-1)
// {
// cout<<0<<endl;
// return 0;
// }
// int ans = 1;
// while(single(grid)==0)
// {
// solve(grid,grid[0][0],0,0);
// ans++;
// }
// cout<<ans<<endl;
// return 0;
// }
int main()
{
int h,w;cin>>h>>w;
vector<vector<char>> grid(h,vector<char>(w));
for(int i=0;i<h;i++)
{
for(int j=0;j<w;j++)
{
cin>>grid[i][j];
}
}
if(single(grid)==-1)
{
cout<<0;return 0;
}
deque<pair<int,int>>current;
current.push_back({0,0});
vector<vector<bool>> vis(h,vector<bool>(w));
vis[0][0] = true;
char curr = grid[0][0];
int ans = 1;
while(current.size())
{
pair<int,int> cur = current.front();
current.pop_front();
int x = cur.first, y = cur.second;
if(grid[x][y]!=curr)
{
curr = grid[x][y];
ans++;
}
// right
if (y + 1 < w && !vis[x][y + 1] && grid[x][y + 1] != '.') {
vis[x][y + 1] = true;
if (grid[x][y] == grid[x][y + 1])
current.push_front({x, y + 1});
else
current.push_back({x, y + 1});
}
// down
if (x + 1 < h && !vis[x + 1][y] && grid[x + 1][y] != '.') {
vis[x + 1][y] = true;
if (grid[x][y] == grid[x + 1][y])
current.push_front({x + 1, y});
else
current.push_back({x + 1, y});
}
// left
if (y - 1 >= 0 && !vis[x][y - 1] && grid[x][y - 1] != '.') {
vis[x][y - 1] = true;
if (grid[x][y] == grid[x][y - 1])
current.push_front({x, y - 1});
else
current.push_back({x, y - 1});
}
// up
if (x - 1 >= 0 && !vis[x - 1][y] && grid[x - 1][y] != '.') {
vis[x - 1][y] = true;
if (grid[x][y] == grid[x - 1][y])
current.push_front({x - 1, y});
else
current.push_back({x - 1, y});
}
}
cout<<ans<<endl;
return 0;
}
