#include <bits/stdc++.h>
#include <iostream>
#define ll long long
using namespace std;
const int N=500010;
int parents[N];
int getparent(int node){
if (parents[node]==-1 || parents[node]==node)return parents[node]=node;
else return parents[node] = getparent(parents[node]);
}
vector<int> connections[N];
vector<int> t_connections[N];
bool covered[N];
int sizep[N];
int main(){
int n,m;cin>>n>>m;
memset(parents, -1, sizeof parents);
for (int i = 0 ; i < m ; ++i){
char w;
int aa,bb;cin>>aa>>bb>>w;
int a,b;
a = (aa>=bb) ? aa : bb;
b = (a==aa) ? bb : aa;
if (w=='T'){
parents[a]=b;
t_connections[a].push_back(b);
}else connections[a].push_back(b);
}
int c=0;
memset(covered, 0, sizeof covered);
memset(sizep, 0, sizeof sizep);
for (int i = 2; i <= n;++i)++sizep[getparent(i)];
c+=sizep[1];
for (int i = 2; i<=n;++i){
int p=getparent(i);
if (p!=1 && !covered[p]){
for (int j = 0; j < connections[i].size();++j){
if (getparent(connections[i][j]) == 1 ){
c+=sizep[p];covered[p]=true;
}
}
}
}
cout<<c<<endl;
return 0;
}
