#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define nl endl
#define loop(i,a,b) for(ll i=a;i<b;i++)
#define rloop(i,a,b) for(ll i=b;i>=a;i--)
#define cy cout<<"YES"<<endl;
#define cn cout<<"NO"<<endl;
#define cm cout<<-1<<endl
#define vl vector<ll>
#define vchar vector<char>
#define vvll vector<vector<ll>>
#define vvcr vector<vchar>
#define deb(x) cout<<#x<<" "<<x<<endl;
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
using namespace std;
const ll MOD=1e9+7;
ll binepow(ll a,ll b,ll mod=-1){
if(b==0){
return 1ll;
}
if(mod!=-1){
ll k=binepow(a,b/2,mod);
if(b%2==0){
return (k*k)%mod;
}
else{
return (((k*a)%mod)*k)%mod;
}
}
else{
ll k=binepow(a,b/2,mod);
if(b%2==0){
return (k*k);
}
else{
return k*k*a;
}
}
}
////////////////////////////////////////////////////////
void solve(){
ll n,m;
cin>>n>>m;
vvcr a(n,vchar(m,'.'));
ll total=0;
loop(i,0,n){
loop(j,0,m){
cin>>a[i][j];
if(a[i][j]!='.'){
total++;
}
}
}
ll ans=0;
char role=a[0][0];
while (total!=0)
{
vvll vis(n,vl(m,0));
queue<pair<ll,ll>> q;
q.push({0,0});
vis[0][0]=1;
while (q.size()!=0)
{
if(a[q.front().first][q.front().second]==role){
a[q.front().first][q.front().second]='x';
total--;
}
ll x=q.front().first,y=q.front().second;
vis[x][y]=1;
if(x>0 && (a[x-1][y]==role || a[x-1][y]=='x' ) && vis[x-1][y]==0){
q.push({x-1,y});
}
if(y>0 && (a[x][y-1]==role || a[x][y-1]=='x' ) && vis[x][y-1]==0){
q.push({x,y-1});
}
if(x<n-1 && (a[x+1][y]==role || a[x+1][y]=='x' ) && vis[x+1][y]==0){
q.push({x+1,y});
}
if(y<m-1 && (a[x][y+1]==role || a[x][y+1]=='x' ) && vis[x][y+1]==0){
q.push({x,y+1});
}
q.pop();
}
ans++;
if(role=='R'){
role='F';
}
else{
role='R';
}
}
cout<<ans<<nl;
return;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);
// ll t;
// cin>>t;
// while(t--){
// solve();
// }
solve();
}
