#include<bits/stdc++.h>
using namespace std;
vector<int> link;
vector<int> sizes;
int find(int x){
while(x!=link[x]) x = link[x];
return x;
}
bool same(int a, int b){
return find(a)==find(b);
}
void unite(int a, int b){
a = find(a);
b = find(b);
if(a!=b){
if(sizes[a]<sizes[b]) swap(a, b);
link[b] = a;
sizes[a] += sizes[b];
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, m;
cin >> n >> m;
vector<pair<int, bool> > adg[n];
vector<pair<int, int> > bus;
link.resize(n);
sizes.resize(n);
int newsize[n];
for(int i=0; i<n; i++){
link[i]=i;
sizes[i]=1;
newsize[i]=0;
}
for(int i=0; i<m; i++){
int a, b;
char t;
cin >> a >> b >> t;
a--;
b--;
adg[a].push_back(make_pair(b, (t=='T')));
adg[b].push_back(make_pair(a, (t=='T')));
if(t=='T') unite(a, b);
else bus.push_back(make_pair(a, b));
}
set<int> newgraph[n];
for(auto u : bus){
if(find(u.first)!=find(u.second)){
if(newgraph[find(u.first)].count(find(u.second))==0){
newsize[find(u.first)]+=sizes[find(u.second)];
newsize[find(u.second)]+=sizes[find(u.first)];
newgraph[find(u.first)].insert(find(u.second));
newgraph[find(u.second)].insert(find(u.first));
}
}
}
int ans = 0;
for(int i=0; i<n; i++){
if(newsize[i]+sizes[i]==n){
ans+=sizes[i];
}
}
cout << ans << '\n';
return 0;
}
