#include <bits/stdc++.h>
#define FLASH ios_base::sync_with_stdio(0);
#define ll long long
#define debt(x,y)cout<<"#x = "<<(x)<<" and "<<"#y = "<<(y)<<endl;
#define deb(x)cout<<"#x = "<<(x)<<endl;
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define endl "\n"
#define arr(a,n) for(ll i=1;i<=n;i++) cout<<a[i]<<" "; cout << "\n";
#define vecc(a,n) for(ll i=0;i<n;i++) cout<<a[i]<<" "; cout << "\n";
using namespace std;
ll n,m;
struct edge
{
ll x,y;
};
vector<edge>bus;
set<ll>adj[500010];
ll par[500010];
ll rankk[500010];
void make_set(ll n)
{
for(ll i=0;i<=n;i++){rankk[i]=1;par[i]=i;}
}
ll findd(ll v)
{
while(par[v]!=v)
{
par[v]=par[par[v]];
v=par[v];
}
return v;
}
void make_union(ll a,ll b)
{
a=findd(a);b=findd(b);
if(a!=b)
{
if(rankk[a]>rankk[b])swap(a,b);
rankk[b]+=rankk[a];
par[a]=par[b];
}
}
int main(){
FLASH;
cin>>n>>m;
make_set(n);
for(ll i=1;i<=m;i++)
{
ll x,y;
char z;
cin>>x>>y>>z;
if(z=='T')
{
make_union(x,y);
}
else bus.pb({x,y});
}
for(auto i:bus)
{
if(findd(i.x)!=findd(i.y))
{
adj[findd(i.x)].insert(findd(i.y));
adj[findd(i.y)].insert(findd(i.x));
}
}
ll cnt=0;
for(ll i=1;i<=n;i++)
{
ll p=findd(i);
if(p==i)
{
cnt++;
}
}
ll ans=0;
for(ll i=1;i<=n;i++)
{
ll p=findd(i);
if(p==i)
{
ll sz=(ll)adj[i].size();
if(sz==cnt-1)ans+=rankk[i];
}
}
cout<<ans<<endl;
return 0;
}
