#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int k, q, a, b;
char A, B;
ll sum=0, ans=0;
priority_queue<int> l;
priority_queue<int, vector<int>, greater<int>> r;
map<int, vector<int>> mp;
map<int, ll> cans;
void upd(int pos) {
if(l.empty()) {
l.push(pos); r.push(pos);
return;
}
if(pos < l.top()) {
sum += l.top()-pos;
l.push(pos);
l.push(pos);
r.push(l.top());
l.pop();
} else if(pos > r.top()) {
sum += pos-r.top();
r.push(pos);
r.push(pos);
l.push(r.top());
r.pop();
} else {
l.push(pos); r.push(pos);
}
}
int main() {
cin.tie(0) -> sync_with_stdio(0);
cin >> k >> q;
while(q--) {
cin >> A >> a >> B >> b;
if(a>b) swap(a, b);
if(A==B) {
ans += b-a;
} else {
ans++;
mp[a].push_back(b);
}
}
ll minminmin = 0;
vector<int> revmap;
for(auto &e:mp) {
revmap.push_back(e.first);
for(auto &E:e.second) {
upd(e.first);
upd(E);
}
cans[e.first] = sum;
minminmin = sum;
}
reverse(revmap.begin(), revmap.end());
sum=0;
while(!l.empty()) l.pop();
while(!r.empty()) r.pop();
for(auto &e:revmap) {
auto &vec = mp[e];
if(k==2) minminmin = min(minminmin, cans[e]+sum);
for(auto &E:vec) {
upd(e);
upd(E);
}
}
cout << ans+minminmin;
}
