#include<bits/stdc++.h>
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(), a.rend()
#define forn(u,n) for(int u=0;u<n;++u)
#define forns(u,i,n) for(int u=i;u<n;++u)
#define todo0(a) memset(a,0,sizeof a)
#define todom1(a) memset(a,-1,sizeof a)
#define reverso int, vector<int>, greater<int>
#define sz(a) ((int)a.size())
#define pb push_back
#define snd second
#define fst first
using namespace std;
typedef long long ll;
const long long MOD = 1000567999;
const int N = 500001;
int parent[N];
int rank_dsu[N];
// Finds representative of DSU
int find_parent(int v) {
return parent[v] = (v == parent[v] ? v : find_parent(parent[v]));
}
void make_set(int v){
parent[v] = v;
rank_dsu[v] = 1;
}
void join(int u, int v){
u = find_parent(u);
v = find_parent(v);
if (u != v){
// Add tree of lower rank_dsued node to the higher one
if (rank_dsu[v] > rank_dsu[u])
swap(u, v);
parent[v] = u;
rank_dsu[u]+=rank_dsu[v];
}
}
int main(){
#ifdef LOCAL
freopen("entra.in","r",stdin);
#endif
ios_base::sync_with_stdio(0);
cin.tie(NULL);
int n,m;
cin>>n>>m;
vector<pair<int,int>>buses;
forns(i,1,n+1){
make_set(i);
}
forn(i,m){
int u,v;
string s;
cin>>u>>v>>s;
if(s=="T"){
join(u,v);
}
else{
buses.pb({u,v});
}
}
set<int>sets;
for(int i=1;i<=n;i++)sets.insert(find_parent(i));
int cnt=(int)sets.size();
ll ans=0;
map<int,set<int>>groups;
for(auto [u,v]:buses){
u=find_parent(u);
v=find_parent(v);
if(u==v)continue;
groups[u].insert(v);
groups[v].insert(u);
}
set<int>taken;
forns(i,1,n+1){
int u=find_parent(i);
if(taken.count(u))continue;
if(1+(int)groups[u].size()==cnt)ans+=rank_dsu[u];
taken.insert(u);
}
cout<<ans<<endl;
}
