/*input
5 5
3 1 A
3 5 A
4 5 T
2 3 T
2 1 A
*/
#include<bits/stdc++.h>
using namespace std;
#define x first
#define y second
vector<int> sz;
vector<int> p;
int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); }
bool isSameSet(int i, int j) { return findSet(i) == findSet(j); }
void unionSet(int i, int j) {
if (isSameSet(i, j)) return;
int x = findSet(i), y = findSet(j);
if (sz[x] < sz[y]) swap(x, y);
p[y] = x;
sz[x] += sz[y];
}
vector<vector<int>> trauk;
vector<set<int>> newEdges;
vector < pair<int, int>> autob;
vector<bool> visited;
void dfs(int curr) {
visited[curr] = true;
// for(int i = 0; i < (int)trauk[curr].size(); i++){
// u = trauk[curr][i];
for (auto u : trauk[curr]) {
if (visited[u]) continue;
unionSet(curr, u);
dfs(u);
}
}
int main() {
int N, M;
cin >> N >> M;
sz = vector<int>(N, 1);
p = vector<int>(N);
trauk = vector<vector<int>>(N);
newEdges = vector<set<int>>(N);
for (int i = 0; i < N; ++i)
p[i] = i;
for (int i = 0; i < M; ++i)
{
int a, b; char ch;
cin >> a >> b >> ch; a--; b--;
if (ch == 'T') {
trauk[a].emplace_back(b);
trauk[b].emplace_back(a);
} else {
autob.emplace_back(a, b);
}
}
visited = vector<bool>(N, false);
for (int i = 0; i < N; ++i)
{
if (!visited[i])
dfs(i);
}
for (int i = 0; i < (int)autob.size(); ++i)
{
pair<int, int> ed = autob[i];
if (isSameSet(ed.x, ed.y)) continue;
newEdges[findSet(ed.x)].insert(findSet(ed.y));
newEdges[findSet(ed.y)].insert(findSet(ed.x));
}
set<int> tevai;
for (int i = 0; i < N; ++i)
{
tevai.insert(findSet(i));
}
int newN = (int)tevai.size();
int ats = 0;
for (auto tevas : tevai) {
if ((int)newEdges[tevas].size() == newN - 1) {
ats += sz[tevas];
}
}
cout << ats << '\n';
}
