//#pragma GCC optimize("O3,unroll-loops,fast-math")
#pragma GCC optimize("O3,Ofast")
//#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
typedef int ll;
using namespace std;
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n , m , ans = 0;cin >> n >> m;
vector<vector<int>> g(n + 1);
vector<vector<int>> g2(n + 1);
for(int i = 1 ; i <= m ; i++){
char ty;
int u , v;cin >> u >> v >> ty;
if(ty == 'T'){g[u].push_back(v); g[v].push_back(u);}
if(ty == 'A'){g2[u].push_back(v); g2[v].push_back(u);}
}
vector<bool> seen (n + 1);vector<int> vc(n + 1);
vector<vector<int>> components;
for(int i = 1 ; i <= n ; i++){
if(seen[i])continue;
vector<int> vertex , que = {i};
seen[i] = 1;
while(!que.empty()){
int u = que.back();
vertex.push_back(u);
que.pop_back();
for(int v : g[u]){
if(seen[v])continue;
que.push_back(v);
seen[v] = 1;
}
}
int idx = components.size();
components.push_back(vertex);
}
vector<bool> mark(components.size());
for(int p = 0 ; p < components.size() ; p++)for(int &u : components[p])vc[u] = p;
for(int p = 0 ; p < components.size() ; p++){
vector<int> opr = {p};
int cnt = 1 ;
mark[p] = 1;
for(int &u : components[p]){
for(int v : g2[u]){
if(!mark[vc[v]]){
opr.push_back(vc[v]);
mark[vc[v]] = 1;
cnt++;
}
}
}
if(cnt == components.size())ans+= components[p].size();
for(int &u : opr)mark[u] = 0;
}
cout << ans;
}
