#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define endl "\n"
#define vec vector<ll>
#define vecvec vector<vector<ll>>
using namespace std;
/*#define FileName ""
string Ghhhh = ".in";
string Ghhhhh = ".out";
ifstream Girdi(FileName + Ghhhh);
ofstream Cikti(FileName + Ghhhhh);
#define cin Girdi
#define cout Cikti*/
#define maxn 100005
ll n,m;
vector<vector<ll>> adj;
vector<ll> komsu_sayisi;
vector<ll> buyukluk;
vector<bool> vis;
vector<ll> component;
vector<pair<ll,ll>> bus;
inline void dfs(ll node, ll component_no){
vis[node] = 1;
component[node] = component_no;
buyukluk[component_no]++;
for(auto go : adj[node]){
if(!vis[go]){
dfs(go,component_no);
}
}
}
inline void solve(){
cin >> n >> m;
adj.resize(n+1);
vis.resize(n+1,0);
component.resize(n+1);
buyukluk.resize(n+1,0);
while(m--){
ll a,b;
char c;
cin >> a >> b >> c;
if(c == 'T'){
adj[a].pb(b);
adj[b].pb(a);
}else{
bus.pb({a,b});
}
}
ll component_no = 1;
for(ll i = 1 ; i <= n ; i++){
if(!vis[i]){
dfs(i,component_no);
component_no++;
}
}
komsu_sayisi.resize(component_no+1);
map<pair<ll,ll>,ll> mapp;
for(auto it : bus){
ll a = component[it.first];
ll b = component[it.second];
if(a > b) swap(a,b);
if(a != b and mapp[{a,b}] < 1){
komsu_sayisi[a]++;
komsu_sayisi[b]++;
mapp[{a,b}]++;
}
}
ll ans = 0;
for(ll i = 1 ; i <= component_no-1 ; i++){
if(komsu_sayisi[i] == component_no-2){
ans += buyukluk[i];
}
}
cout << ans << endl;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll t = 1;
//cin >> t;
while(t--){
solve();
}
}
