#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]==node)return parents[node]=node;
else return parents[node] = getparent(parents[node]);
}
vector<pair<int,int>> connections2;
set<int> connections[N];
bool covered[N];
bool covered2[N];
int sizep[N];
int main(){
int n,m;cin>>n>>m;
memset(sizep,0,sizeof sizep);
memset(covered,0, sizeof covered);
memset(covered2,0, sizeof covered2);
set<int> amongos;
for (int i=1;i<=n;++i){parents[i]=i;sizep[i]++;amongos.insert(i);}
for (int i = 0;i<m;++i){
char w;int a,b;cin>>a>>b>>w;
int pa=getparent(a);
int pb=getparent(b);
if (w=='T'){
if (pa!=pb){
if (sizep[pa]>sizep[pb]){
sizep[pa]+=sizep[pb];
parents[pb]=pa;
amongos.erase(pb);
}else{
sizep[pb]+=sizep[pa];
parents[pa]=pb;
amongos.erase(pa);
}
}
}else{
connections2.push_back({a,b});
}
}
for (pair<int,int> it : connections2){
int pa = getparent(it.first);
int pb = getparent(it.second);
if (pa!=pb){
connections[pa].insert(pb);
connections[pb].insert(pa);
}
}
int c=0;
for (auto nodeichon : amongos)if (connections[nodeichon].size() == amongos.size()-1)c+=sizep[nodeichon];
cout<<c;
return 0;
}
