#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ordered_set <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset <int, null_type, less_equal <int>, rb_tree_tag, tree_order_statistics_node_update>
#define int long long
#define double long double
#define pii pair <int, int>
#define tiii tuple <int, int, int>
#define emb emplace_back
#define all(a) a.begin(), a.end()
#define iShowSpeed cin.tie(NULL)->sync_with_stdio(false)
const int mod = 1e9 + 7;
const int inf = 1e18;
const int N = 5e5 + 5;
int n, m, par[N];
vector <pii> edge;
int dsu(int a){
return par[a] = (a == par[a] ? a : dsu(par[a]));
}
int32_t main(){
iShowSpeed;
iota(par, par + N, 0ll);
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v; char c; cin >> u >> v >> c;
if (c == 'T') {
if (dsu(u) != dsu(v)) par[dsu(u)] = dsu(v);
}
else {
edge.emb(u, v);
}
}
unordered_map <int, int> mp, sz;
int cnt = 0;
for (int i = 1; i <= n; i++) {
int a = dsu(i);
if (mp.find(a) == mp.end()) mp[a] = ++cnt;
sz[mp[a]]++;
}
set <int> bus[n + 1];
for (auto [u, v] : edge) {
int a = dsu(u), b = dsu(v);
if (a != b) {
// cout << u << " " << v << "\n";
bus[mp[a]].emplace(mp[b]);
bus[mp[b]].emplace(mp[a]);
}
}
// for (int i = 1; i <= cnt; i++) {
// cout << i << ": ";
// cout << sz[i] << ": ";
// for (auto e : bus[i]) cout << e << " ";
// cout << "\n";
// }
int ans = 0;
for (int i = 1; i <= cnt; i++) {
if (bus[i].size() == cnt - 1) ans += sz[i];
}
cout << ans;
}
