#include <bits/stdc++.h>
using namespace std;
struct DSU
{
vector<int> tata, rsz;
DSU(int n) : tata(n), rsz(n, 0)
{
for (int i = 0; i < n; i++)
tata[i] = i;
}
int find_set(int v)
{
if (tata[v] == v) return v;
tata[v] = find_set(tata[v]);
return tata[v];
}
void union_set(int a, int b)
{
a = find_set(a);
b = find_set(b);
if (a != b)
{
if (rsz[a] < rsz[b]) tata[a] = b;
else if (rsz[a] > rsz[b]) tata[b] = a;
else tata[b] = a, rsz[a]++;
}
}
};
int main()
{
int n, m;
cin >> n >> m;
vector<pair<int,int>> tedge;
vector<pair<int,int>> bedge;
for(int i = 0; i < m; i++)
{
int a, b;
char ch;
cin >> a >> b >> ch;
a--;
b--;
if(ch == 'T') tedge.push_back({a, b});
else bedge.push_back({a, b});
}
DSU dsu(n);
for(auto &e : tedge)
dsu.union_set(e.first, e.second);
unordered_map<int,int> dtoid;
vector<int> compid(n);
int nextid = 0;
for(int i = 0; i < n; i++)
{
int r = dsu.find_set(i);
if(!dtoid.count(r))
dtoid[r] = nextid++;
compid[i] = dtoid[r];
}
int k = nextid;
if(k == 1)
{
cout << n << "\n";
return 0;
}
vector< unordered_set<int> > adj(k);
for(auto &e : bedge)
{
int c1 = compid[e.first];
int c2 = compid[e.second];
if(c1 != c2)
{
adj[c1].insert(c2);
adj[c2].insert(c1);
}
}
vector<int> compsz(k, 0);
for(int i = 0; i < n; i++)
compsz[compid[i]]++;
long long ans = 0;
for(int i = 0; i < k; i++)
if((int)adj[i].size() == k - 1)
ans += compsz[i];
cout << ans;
return 0;
}
